diff --git a/plugins/kyberforge/skills/marketplace-author/SKILL.md b/plugins/kyberforge/skills/marketplace-author/SKILL.md
index d82b8c1..317e0a4 100644
--- a/plugins/kyberforge/skills/marketplace-author/SKILL.md
+++ b/plugins/kyberforge/skills/marketplace-author/SKILL.md
@@ -7,14 +7,16 @@ description: >
   the marketplace version", "update the description for Y"). Always updates
   both .claude-plugin/marketplace.json and .github/plugin/marketplace.json in
   the same pass. Out of scope: plugin scaffold and configuration — use
-  /plugin-author for that. Does not manage marketplace registration with
-  Claude Code or Copilot CLI.
+  /plugin-author for that. Does not run `claude plugin marketplace add` or
+  equivalent CLI registration commands — only manages `marketplace.json`
+  entries.
 allowed-tools: Bash Read Write Edit
 metadata:
   category: factory
   source_keys:
     - context7-websites-code-claude
     - claude-code-plugins-docs
+    - context7-github-en-copilot
     - github-cli-plugin-reference
     - github-plugins-marketplace
     - github-plugins-finding-installing
@@ -31,8 +33,8 @@ metadata:
 - `name` must be kebab-case. Reserved prefixes (`anthropic-*`, `claude-*`, `agent-skills`, `official-claude-plugins`) are rejected by the validator.
 - The `plugins[]` array order is not semantically significant, but maintain it consistently — add new entries at the end.
 - For Copilot CLI, the canonical marketplace.json location is `.github/plugin/marketplace.json`. Claude Code also reads `.claude-plugin/marketplace.json`. Both are equivalent; this repo maintains both files in sync.
-
-Read `references/manifest-fields.md` for the full field reference and source type shapes before editing any file.
+- Copilot CLI places top-level `description` and `version` under a `metadata` object (`metadata.description`, `metadata.version`). Claude Code accepts them at the top level. For dual-tool repos, use the `metadata` form — it is valid in both tools.
+- Set `"strict": false` on a plugin entry to allow relaxed schema validation for that entry. This is the right choice for plugins distributed as `.claude-plugin/` directories that also serve Claude Code — it prevents Copilot CLI from failing on CC-specific fields that are not in the Copilot schema.
 
 ## Route
 
@@ -70,8 +72,10 @@ Create the file with the following structure (fill in the values from prerequisi
 {
   "name": "<marketplace-name>",
   "owner": { "name": "<owner-name>", "email": "<owner-email>" },
-  "description": "<marketplace-description>",
-  "version": "0.1.0",
+  "metadata": {
+    "description": "<marketplace-description>",
+    "version": "0.1.0"
+  },
   "plugins": [
     {
       "name": "<plugin-name>",
@@ -82,7 +86,7 @@ Create the file with the following structure (fill in the values from prerequisi
 }
 ```
 
-Omit `"email"` if not provided. Omit `"version"` from plugin entries unless the user specifies one (see Gotchas).
+Omit `"email"` if not provided. Omit `"metadata.version"` if the user does not want a pinned catalog version. The `metadata` object is the Copilot CLI canonical location for top-level description and version — Claude Code accepts both `metadata`-nested and top-level forms; use `metadata` for dual-tool repos.
 
 ### Step 2 — Write `.github/plugin/marketplace.json`
 
@@ -106,6 +110,8 @@ Confirm you have:
 - [ ] Source type and source value (see source type branching below)
 - [ ] Version (optional; omit for git-sourced plugins)
 
+If you need details on a specific source type shape or per-entry optional fields, read `references/manifest-fields.md`.
+
 ### Source type branching
 
 If the user has not specified a source type, ask:
@@ -127,7 +133,7 @@ Source shapes per type:
 ```json
 "source": { "source": "github", "repo": "owner/repo" }
 ```
-Add `"ref": "<branch-or-tag>"` inside the object if the user specifies a branch or tag.
+Add `"ref": "<branch-or-tag>"` inside the object if the user specifies a branch or tag. Add `"sha": "<commit-sha>"` if pinning to an exact commit — `sha` takes precedence over `ref` when both are present.
 
 **Git URL:**
 ```json
@@ -155,6 +161,8 @@ The full entry added to `plugins[]`:
 
 Include `"version": "<version>"` at the entry level only when the source is npm or when the user explicitly requests a pinned version in the catalog.
 
+Include `"strict": false` when the plugin is a dual Claude Code / Copilot CLI plugin — this prevents Copilot from rejecting CC-specific fields in the plugin directory.
+
 ### Step 1 — Read both files
 
 Read `.claude-plugin/marketplace.json` and `.github/plugin/marketplace.json`. Verify they are identical. If they differ, stop and report the divergence — do not proceed until the user resolves it.
@@ -205,6 +213,8 @@ Follow the **VALIDATE** flow.
 
 Run this flow when an entry exists in `plugins[]` and the intent is to change one or more fields.
 
+If you need to verify a field name or source type shape, read `references/manifest-fields.md`.
+
 ### Step 1 — Read the current entry
 
 Read `.claude-plugin/marketplace.json`. Show the current state of the target entry so the user can confirm the fields to change.
@@ -226,9 +236,11 @@ Follow the **VALIDATE** flow.
 Run `claude plugin validate .` from the repo root:
 
 ```bash
-cd <repo-root> && claude plugin validate .
+claude plugin validate .
 ```
 
+Add `--strict` to promote warnings to errors — recommended in CI.
+
 Report the output. If validation fails, describe the specific error and what needs to be fixed. Do not attempt to auto-fix validation errors unless the fix is unambiguous (e.g. a trailing comma that violates JSON syntax); otherwise, describe the fix and ask the user to confirm.
 
 Validation checks include: `marketplace.json` schema compliance, duplicate plugin names, source path traversal, and version mismatches.
diff --git a/plugins/kyberforge/skills/marketplace-author/references/manifest-fields.md b/plugins/kyberforge/skills/marketplace-author/references/manifest-fields.md
index fc1356b..b766d97 100644
--- a/plugins/kyberforge/skills/marketplace-author/references/manifest-fields.md
+++ b/plugins/kyberforge/skills/marketplace-author/references/manifest-fields.md
@@ -2,6 +2,7 @@
 source_keys:
   - context7-websites-code-claude
   - claude-code-plugins-docs
+  - context7-github-en-copilot
   - github-cli-plugin-reference
   - github-plugins-marketplace
 ---
@@ -27,8 +28,9 @@ Both files must be kept identical at all times. Every operation that modifies on
 |---|---|---|---|
 | `name` | Yes | string | Marketplace name. Kebab-case, max 64 chars. Becomes the marketplace identifier used in `plugin install <name>@<marketplace>`. |
 | `owner` | Yes | object | `{ "name": string, "email"?: string }` — the marketplace maintainer. |
-| `description` | No | string | Human-readable description of the marketplace. Not in all schemas but accepted and displayed in the Discover tab. |
-| `version` | No | string | Marketplace-level version string. Used for catalog caching; bump when the plugin list changes significantly. |
+| `metadata` | No | object | `{ "description"?: string, "version"?: string, "pluginRoot"?: string }` — Copilot CLI canonical location for top-level description and version. Claude Code also accepts `description` and `version` directly at the top level; use `metadata` for dual-tool repos. |
+| `description` | No | string | Top-level description — Claude Code only. For dual-tool repos, prefer `metadata.description` instead. |
+| `version` | No | string | Top-level marketplace version — Claude Code only. For dual-tool repos, prefer `metadata.version` instead. |
 | `plugins` | Yes | array | Array of plugin entry objects. See Per-Entry Fields below. |
 
 ---
@@ -42,6 +44,19 @@ Both files must be kept identical at all times. Every operation that modifies on
 | `description` | No | string | Human-readable plugin description. Max 1024 chars (Copilot CLI schema). Displayed in browse output. |
 | `version` | No | string | Pinned version for catalog display. Optional for git-sourced plugins — Claude Code derives version from git tags. Required for npm source. Include when the user wants an explicit pinned version visible in the catalog. |
 | `author` | No | object | `{ "name": string, "email"?: string, "url"?: string }` — the plugin author. |
+| `homepage` | No | string | URL for the plugin homepage or docs site. |
+| `repository` | No | string | URL for the plugin source repository. |
+| `license` | No | string | SPDX license identifier (e.g. `"MIT"`, `"Apache-2.0"`). |
+| `keywords` | No | string[] | Search terms for discovery (feeds into Discover tab search index). |
+| `category` | No | string | Single category label for grouping in the Discover tab. |
+| `tags` | No | string[] | Additional classification tags. |
+| `agents` | No | string or string[] | Override the path(s) to agent definition files inside the plugin directory. Defaults to `agents/`. |
+| `skills` | No | string or string[] | Override the path(s) to skill directories inside the plugin. Defaults to `skills/`. |
+| `commands` | No | string or string[] | Override the path(s) to command definition files. |
+| `hooks` | No | string or object | Override the path(s) to hook definitions. |
+| `mcpServers` | No | string or object | Override MCP server configuration for the plugin. |
+| `lspServers` | No | string or object | Override LSP server configuration for the plugin. |
+| `strict` | No | boolean | Default `true`. Set to `false` for relaxed schema validation — allows extra or CC-specific fields without failing Copilot CLI validation. Use this for dual Claude Code / Copilot CLI plugins. |
 
 ---
 
diff --git a/plugins/kyberforge/skills/marketplace-author/references/sources.md b/plugins/kyberforge/skills/marketplace-author/references/sources.md
index 780fce3..b223b5e 100644
--- a/plugins/kyberforge/skills/marketplace-author/references/sources.md
+++ b/plugins/kyberforge/skills/marketplace-author/references/sources.md
@@ -2,6 +2,7 @@
 source_keys:
   - context7-websites-code-claude
   - claude-code-plugins-docs
+  - context7-github-en-copilot
   - github-cli-plugin-reference
   - github-plugins-marketplace
   - github-plugins-finding-installing
@@ -25,6 +26,22 @@ source_keys:
 - **Contributing files:** SKILL.md, references/manifest-fields.md
 - **Status:** `extracted`
 
+## claude-code-subagents-docs
+
+- **URL:** https://code.claude.com/docs/en/sub-agents
+- **Research doc:** plugins/kyberforge/docs/research/docs/claude-code-plugins/sources.md
+- **Description:** Official Claude Code subagent reference — definition format, all frontmatter fields, scope priority, built-in agents, CLI flags, environment variables, known limitations
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## context7-github-en-copilot
+
+- **URL:** context7:/websites/github_en_copilot
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Official GitHub Copilot documentation indexed by Context7; covers CLI plugins, custom agents, SDK, and marketplace — including `metadata` object schema, per-entry optional fields, `strict` field behavior
+- **Contributing files:** SKILL.md, references/manifest-fields.md
+- **Status:** `extracted`
+
 ## github-cli-plugin-reference
 
 - **URL:** https://docs.github.com/en/copilot/reference/copilot-cli-reference/cli-plugin-reference
@@ -48,3 +65,83 @@ source_keys:
 - **Description:** User-facing guide to discovering and installing CLI plugins — marketplace browsing commands, install/update/uninstall workflow; informs REMOVE flow design (unlisting does not uninstall from existing users)
 - **Contributing files:** SKILL.md
 - **Status:** `extracted`
+
+## github-custom-agents-configuration
+
+- **URL:** https://docs.github.com/en/copilot/reference/custom-agents-configuration
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Reference for cloud and IDE custom agent definition format — frontmatter fields, tool aliases, MCP server config, secrets interpolation, scoping hierarchy
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-plugins-creating
+
+- **URL:** https://docs.github.com/en/copilot/how-tos/copilot-cli/customize-copilot/plugins-creating
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** How-to for creating Copilot CLI plugins — plugin structure, agent and skill authoring, hooks format, MCP config, development lifecycle
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-sdk-custom-agents
+
+- **URL:** https://docs.github.com/en/copilot/how-tos/copilot-sdk/features/custom-agents
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** SDK custom agent API — CustomAgentConfig fields in all five languages, session config, sub-agent lifecycle events, tool scoping, permission handling
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-changelog-copilot-extensions-ga
+
+- **URL:** https://github.blog/changelog/2025-02-19-announcing-the-general-availability-of-github-copilot-extensions/
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Announcement of GitHub Copilot Extensions general availability (February 2025) — OIDC auth, all license tiers, VS Code/Visual Studio/JetBrains/GitHub.com support
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-changelog-copilot-extensions-sunset
+
+- **URL:** https://github.blog/changelog/2025-09-24-deprecate-github-copilot-extensions-github-apps/
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Sunset notice for GitHub App-based Copilot Extensions — creation blocked Sep 24, 2025; full shutdown Nov 10, 2025; MCP servers recommended as replacement
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-docs-copilot-extensions-skillsets
+
+- **URL:** https://docs.github.com/en/copilot/concepts/build-copilot-extensions/skillsets-for-copilot-extensions
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Concept doc for Copilot Extension skillsets — up to 5 skills per extension, Copilot handles routing/prompt crafting/response, contrast with agent extensions
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-docs-copilot-extensions-building
+
+- **URL:** https://docs.github.com/en/copilot/building-copilot-extensions/setting-up-copilot-extensions
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** How-to for setting up a Copilot Extension — GitHub App registration, Copilot Chat permission, Copilot Editor Context permission, backend URL configuration
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## vscode-chat-participant-api
+
+- **URL:** https://code.visualstudio.com/api/extension-guides/ai/chat
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** VS Code Chat Participant API — createChatParticipant(), package.json contributes.chatParticipants, Language Model API, @mention invocation in Copilot Chat
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-marketplace-copilot-extensions
+
+- **URL:** https://github.com/marketplace?type=apps&copilot_app=true
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** GitHub Marketplace listing for Copilot Extensions — browsable list of available extensions (historical; page remains live but product is sunset)
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-docs-marketplace-listing-requirements
+
+- **URL:** https://docs.github.com/en/apps/github-marketplace/creating-apps-for-github-marketplace/requirements-for-listing-an-app
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Requirements for listing a GitHub App on the GitHub Marketplace — verified publisher, capability description, UX stability, submission and review process
+- **Contributing files:** (none)
+- **Status:** `referenced`
diff --git a/plugins/kyberforge/skills/plugin-author/README.md b/plugins/kyberforge/skills/plugin-author/README.md
index 50f742b..0a757da 100644
--- a/plugins/kyberforge/skills/plugin-author/README.md
+++ b/plugins/kyberforge/skills/plugin-author/README.md
@@ -37,4 +37,3 @@ bash scripts/new-plugin.sh data-tools .
 | `references/sources.md` | Research provenance — sources that informed this skill |
 | `scripts/README.md` | Directory meta-documentation for scripts/ |
 | `references/README.md` | Directory meta-documentation for references/ |
-| `tests/README.md` | Test dependency instructions and run command |
diff --git a/plugins/kyberforge/skills/plugin-author/SKILL.md b/plugins/kyberforge/skills/plugin-author/SKILL.md
index b7f0895..8b6f2c1 100644
--- a/plugins/kyberforge/skills/plugin-author/SKILL.md
+++ b/plugins/kyberforge/skills/plugin-author/SKILL.md
@@ -6,14 +6,17 @@ description: >
   description", "add keyword", "bump version"), or release a plugin version
   ("release", "tag", "publish"). Manages both Claude Code
   (.claude-plugin/plugin.json) and Copilot CLI (plugin.json) manifests in one
-  pass. Explicitly out of scope: plugin content (skills, agents, hooks, MCP
-  servers) and marketplace.json entries — use /marketplace-author for those.
+  pass. Do not use when the request is about plugin content (skills, agents,
+  hooks, MCP servers) or marketplace.json entries — use /marketplace-author
+  for those.
 allowed-tools: Bash Read Write Edit
 metadata:
   category: factory
   source_keys:
     - context7-websites-code-claude
     - claude-code-plugins-docs
+    - claude-code-subagents-docs
+    - context7-github-en-copilot
     - github-cli-plugin-reference
     - github-plugins-creating
     - github-plugins-finding-installing
@@ -22,12 +25,14 @@ metadata:
 ## Gotchas
 
 - Both manifests must carry identical `version` values — version parity is a hard invariant (ADR-0016). Never update version in one manifest without updating the other in the same edit pass.
-- `author.email` belongs in the Copilot manifest (`plugin.json`); `author.url` belongs in the CC manifest (`.claude-plugin/plugin.json`). Do not swap them.
+- `author.email` is placed in the Copilot manifest by convention; `author.url` is placed in the CC manifest by convention. Both fields are supported by both platforms — do not add them to the other manifest without a deliberate reason.
 - `claude plugin tag --push` is irreversible: it creates a git tag and pushes it to remote. Always present the HITL gate and wait for explicit confirmation before running it.
+- `claude plugin tag --push` requires a clean working tree and will fail if there are uncommitted changes. Commit or stash all changes before running it.
 - `name` in both manifests must be kebab-case and must not use reserved prefixes: `anthropic-*`, `claude-*`, `agent-skills`, `official-claude-plugins`.
 - Copilot manifest lookup order: `.plugin/plugin.json` → `plugin.json` → `.github/plugin/plugin.json` → `.claude-plugin/plugin.json`. The canonical location for the Copilot manifest in this repo is `plugin.json` at the plugin root.
-- `displayName` is CC-only — do not add it to the Copilot manifest.
-- `skills`, `agents`, `hooks`, `mcpServers` are Copilot-only fields — do not add them to the CC manifest.
+- `displayName` is a CC platform field — Copilot has no equivalent. Do not add it to the Copilot manifest.
+- `skills`, `agents`, `hooks`, `mcpServers` are declared in the Copilot manifest by convention — Copilot requires explicit path declarations while CC auto-discovers content from the plugin root. Both platforms support these fields; omit them from the CC manifest by convention.
+- Agent files in a plugin's `agents/` directory silently ignore `hooks`, `mcpServers`, and `permissionMode` frontmatter fields.
 
 ## Route
 
@@ -38,7 +43,7 @@ Determine which flow before touching the filesystem. Read both manifest files if
 - **Plugin directory exists + field change intent** ("update description", "add keyword", "change author") → follow **UPDATE flow**
 - **Ambiguous** → ask: "Did you mean to create a new plugin, update its configuration, or release a version?"
 
-Validate runs automatically before tagging (in RELEASE flow) and can be invoked explicitly at any time.
+Validate runs automatically before tagging (in RELEASE flow) and can be invoked explicitly at any time: `claude plugin validate plugins/<name>`.
 
 ## CREATE flow
 
@@ -83,13 +88,13 @@ Open both manifest files and replace every `FILL_IN_*` placeholder.
 - `license` — SPDX identifier (default: `MIT`)
 - `keywords` — search/discovery tags (default: `[]`)
 
-**CC-only fields** (`.claude-plugin/plugin.json` only):
-- `displayName` — human-readable name shown in plugin manager; capitalised form of `name`
-- `author.url` — author URL (e.g. Gitea profile URL)
+**CC manifest fields** (`.claude-plugin/plugin.json` only):
+- `displayName` — human-readable name shown in plugin manager; capitalised form of `name` (CC platform field — no Copilot equivalent)
+- `author.url` — author URL (e.g. Gitea profile URL) (both platforms support this; placed here by convention)
 
-**Copilot-only fields** (`plugin.json` only):
-- `author.email` — author email
-- `skills`, `agents`, `hooks`, `mcpServers` — paths; defaults are already set by the script
+**Copilot manifest fields** (`plugin.json` only):
+- `author.email` — author email (both platforms support this; placed here by convention)
+- `skills`, `agents`, `hooks`, `mcpServers` — paths; defaults are already set by the script (CC auto-discovers these; Copilot requires explicit declarations)
 
 ### Step 3 — Validate
 
@@ -116,11 +121,15 @@ For every field the user wants to change:
 | Change type | What to update |
 |---|---|
 | Shared field (`name`, `description`, `version`, `author.name`, `license`, `keywords`) | Both manifests in the same edit pass |
-| CC-only (`displayName`, `author.url`) | `.claude-plugin/plugin.json` only |
-| Copilot-only (`author.email`, `skills`, `agents`, `hooks`, `mcpServers`, `category`, `tags`, `extensions`) | `plugin.json` only |
+| CC platform field (`displayName`) | `.claude-plugin/plugin.json` only — Copilot has no equivalent field |
+| Copilot platform fields (`category`, `tags`, `extensions`) | `plugin.json` only — not in the CC manifest schema |
+| CC scaffold convention (`author.url`) | `.claude-plugin/plugin.json` only — both platforms support this field; it is placed here by convention |
+| Copilot scaffold convention (`author.email`, `skills`, `agents`, `hooks`, `mcpServers`) | `plugin.json` only by convention — CC also supports these fields; CC auto-discovers content from the plugin root rather than requiring explicit path declarations |
 
 Never update a shared field in one manifest without updating the other in the same pass.
 
+If the target field is not listed in the classification table, read `references/manifest-fields.md` for the full field list and platform support notes.
+
 ### Step 3 — Announce and apply
 
 State which fields change and which files are affected. Then apply. For `version` changes not part of a release, bump both manifests in the same edit.
@@ -147,6 +156,8 @@ Run:
 claude plugin validate plugins/<name>
 ```
 
+Use `--strict` to promote warnings to errors: `claude plugin validate --strict plugins/<name>`.
+
 Stop and report errors if validation fails. Do not proceed to tagging until validation passes.
 
 ### Step 4 — HITL gate
@@ -159,6 +170,8 @@ Do not call the tool until the user explicitly confirms in the conversation.
 
 ### Step 5 — Tag and release
 
+To preview without tagging or pushing: `claude plugin tag --dry-run`.
+
 After explicit confirmation, run from the repo root:
 
 ```bash
diff --git a/plugins/kyberforge/skills/plugin-author/references/manifest-fields.md b/plugins/kyberforge/skills/plugin-author/references/manifest-fields.md
index 9a68788..49b3040 100644
--- a/plugins/kyberforge/skills/plugin-author/references/manifest-fields.md
+++ b/plugins/kyberforge/skills/plugin-author/references/manifest-fields.md
@@ -3,6 +3,7 @@ topic: manifest-fields
 source_keys:
   - context7-websites-code-claude
   - claude-code-plugins-docs
+  - context7-github-en-copilot
   - github-cli-plugin-reference
   - github-plugins-creating
   - github-plugins-finding-installing
@@ -14,6 +15,10 @@ This document covers optional fields beyond the scaffolded defaults. Consult it
 
 ## Field Classification
 
+Fields fall into three categories: **shared** (identical in both manifests), **platform** (one platform does not support the field at all), and **convention** (both platforms support the field, but the repo scaffold places it in one manifest only).
+
+> CC auto-discovers content (skills, agents, hooks, MCP servers) from the plugin root; Copilot requires explicit path declarations. Convention fields in the CC manifest are omitted unless you have a deliberate reason to add them.
+
 | Field | Copilot `plugin.json` | CC `.claude-plugin/plugin.json` | Notes |
 |---|---|---|---|
 | `name` | Yes (shared) | Yes (shared) | Identical in both; kebab-case; max 64 chars (Copilot) |
@@ -22,16 +27,16 @@ This document covers optional fields beyond the scaffolded defaults. Consult it
 | `author.name` | Yes (shared) | Yes (shared) | Identical in both |
 | `license` | Yes (shared) | Yes (shared) | Identical in both; SPDX identifier |
 | `keywords` | Yes (shared) | Yes (shared) | Identical in both; string array |
-| `displayName` | No | Yes (CC-only) | Human-readable name shown in plugin manager |
-| `author.url` | No | Yes (CC-only) | Author profile or homepage URL |
-| `author.email` | Yes (Copilot-only) | No | Author contact email |
-| `agents` | Yes (Copilot-only) | No | Path or array; default: `agents/` |
-| `skills` | Yes (Copilot-only) | No | Path or array; default: `skills/` |
-| `hooks` | Yes (Copilot-only) | No | Path to hooks config |
-| `mcpServers` | Yes (Copilot-only) | No | Path or object for MCP server config |
-| `category` | Yes (Copilot-only) | No | Marketplace category string |
-| `tags` | Yes (Copilot-only) | No | Additional taxonomy tags (distinct from `keywords`) |
-| `extensions` | Yes (Copilot-only) | No | Path, array, or `{ paths, exclusive: true }` to disable built-ins |
+| `displayName` | No (unsupported) | Yes | CC platform field — Copilot has no equivalent |
+| `author.url` | Omitted (convention) | Yes (convention) | Author profile URL; CC scaffold places here; Copilot also supports this field |
+| `author.email` | Yes (convention) | Omitted (convention) | Author email; Copilot scaffold places here; CC also supports this field |
+| `agents` | Yes (convention) | Omitted (convention) | Path or array; default: `agents/`; Copilot requires explicit declaration; CC auto-discovers |
+| `skills` | Yes (convention) | Omitted (convention) | Path or array; default: `skills/`; Copilot requires explicit declaration; CC auto-discovers |
+| `hooks` | Yes (convention) | Omitted (convention) | Path to hooks config; Copilot requires explicit declaration; CC auto-discovers |
+| `mcpServers` | Yes (convention) | Omitted (convention) | Path or object; Copilot requires explicit declaration; CC auto-discovers |
+| `category` | Yes | No (unsupported) | Marketplace category string; Copilot platform field — not in CC manifest schema |
+| `tags` | Yes | No (unsupported) | Additional taxonomy tags (distinct from `keywords`); Copilot platform field |
+| `extensions` | Yes | No (unsupported) | Path, array, or `{ paths, exclusive: true }` to disable built-ins; Copilot platform field |
 | `homepage` | Both (independent) | Both (independent) | Documentation URL; not required to be identical |
 | `repository` | Both (independent) | Both (independent) | Source repo URL |
 
diff --git a/plugins/kyberforge/skills/plugin-author/references/sources.md b/plugins/kyberforge/skills/plugin-author/references/sources.md
index 6a3b6fa..7ec5ffe 100644
--- a/plugins/kyberforge/skills/plugin-author/references/sources.md
+++ b/plugins/kyberforge/skills/plugin-author/references/sources.md
@@ -2,9 +2,21 @@
 source_keys:
   - context7-websites-code-claude
   - claude-code-plugins-docs
+  - claude-code-subagents-docs
+  - context7-github-en-copilot
   - github-cli-plugin-reference
   - github-plugins-creating
   - github-plugins-finding-installing
+  - github-custom-agents-configuration
+  - github-plugins-marketplace
+  - github-sdk-custom-agents
+  - github-changelog-copilot-extensions-ga
+  - github-changelog-copilot-extensions-sunset
+  - github-docs-copilot-extensions-skillsets
+  - github-docs-copilot-extensions-building
+  - vscode-chat-participant-api
+  - github-marketplace-copilot-extensions
+  - github-docs-marketplace-listing-requirements
 ---
 
 # Sources
@@ -30,7 +42,7 @@ source_keys:
 - **URL:** https://docs.github.com/en/copilot/reference/copilot-cli-reference/cli-plugin-reference
 - **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
 - **Description:** Full Copilot CLI plugin reference — `plugin.json` schema (all fields, types, constraints), marketplace.json schema, CLI commands, manifest lookup order
-- **Contributing files:** SKILL.md, scripts/new-plugin.sh, references/manifest-fields.md
+- **Contributing files:** SKILL.md, references/manifest-fields.md
 - **Status:** `extracted`
 
 ## github-plugins-creating
@@ -38,7 +50,7 @@ source_keys:
 - **URL:** https://docs.github.com/en/copilot/how-tos/copilot-cli/customize-copilot/plugins-creating
 - **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
 - **Description:** How-to for creating Copilot CLI plugins — plugin structure, Copilot manifest fields, development lifecycle, hooks format, MCP config
-- **Contributing files:** SKILL.md, scripts/new-plugin.sh
+- **Contributing files:** SKILL.md
 - **Status:** `extracted`
 
 ## github-plugins-finding-installing
@@ -48,3 +60,99 @@ source_keys:
 - **Description:** Finding and installing Copilot CLI plugins — install spec formats, marketplace registration, `copilot plugin` CLI commands
 - **Contributing files:** SKILL.md
 - **Status:** `extracted`
+
+## claude-code-subagents-docs
+
+- **URL:** https://code.claude.com/docs/en/sub-agents
+- **Research doc:** plugins/kyberforge/docs/research/docs/claude-code-plugins/sources.md
+- **Description:** Official Claude Code subagent reference — definition format, all frontmatter fields, scope priority, built-in agents, CLI flags, environment variables, known limitations
+- **Contributing files:** SKILL.md
+- **Status:** `extracted`
+
+## context7-github-en-copilot
+
+- **URL:** context7:/websites/github_en_copilot
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Official GitHub Copilot documentation indexed by Context7; covers CLI plugins, custom agents, SDK, and marketplace
+- **Contributing files:** SKILL.md, references/manifest-fields.md
+- **Status:** `extracted`
+
+## github-custom-agents-configuration
+
+- **URL:** https://docs.github.com/en/copilot/reference/custom-agents-configuration
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Reference for cloud and IDE custom agent definition format — frontmatter fields, tool aliases, MCP server config, secrets interpolation, scoping hierarchy
+- **Contributing files:** (none)
+- **Status:** `extracted`
+
+## github-plugins-marketplace
+
+- **URL:** https://docs.github.com/en/copilot/how-tos/copilot-cli/customize-copilot/plugins-marketplace
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** How-to for creating and publishing a plugin marketplace — marketplace.json structure, hosting options, registration commands
+- **Contributing files:** (none)
+- **Status:** `extracted`
+
+## github-sdk-custom-agents
+
+- **URL:** https://docs.github.com/en/copilot/how-tos/copilot-sdk/features/custom-agents
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** SDK custom agent API — CustomAgentConfig fields in all five languages, session config, sub-agent lifecycle events, tool scoping, permission handling
+- **Contributing files:** (none)
+- **Status:** `extracted`
+
+## github-changelog-copilot-extensions-ga
+
+- **URL:** https://github.blog/changelog/2025-02-19-announcing-the-general-availability-of-github-copilot-extensions/
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Announcement of GitHub Copilot Extensions general availability (February 2025) — OIDC auth, all license tiers, VS Code/Visual Studio/JetBrains/GitHub.com support
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-changelog-copilot-extensions-sunset
+
+- **URL:** https://github.blog/changelog/2025-09-24-deprecate-github-copilot-extensions-github-apps/
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Sunset notice for GitHub App-based Copilot Extensions — creation blocked Sep 24, 2025; full shutdown Nov 10, 2025; MCP servers recommended as replacement
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-docs-copilot-extensions-skillsets
+
+- **URL:** https://docs.github.com/en/copilot/concepts/build-copilot-extensions/skillsets-for-copilot-extensions
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Concept doc for Copilot Extension skillsets — up to 5 skills per extension, Copilot handles routing/prompt crafting/response, contrast with agent extensions
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-docs-copilot-extensions-building
+
+- **URL:** https://docs.github.com/en/copilot/building-copilot-extensions/setting-up-copilot-extensions
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** How-to for setting up a Copilot Extension — GitHub App registration, Copilot Chat permission, Copilot Editor Context permission, backend URL configuration
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## vscode-chat-participant-api
+
+- **URL:** https://code.visualstudio.com/api/extension-guides/ai/chat
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** VS Code Chat Participant API — createChatParticipant(), package.json contributes.chatParticipants, Language Model API, @mention invocation in Copilot Chat
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-marketplace-copilot-extensions
+
+- **URL:** https://github.com/marketplace?type=apps&copilot_app=true
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** GitHub Marketplace listing for Copilot Extensions — browsable list of available extensions (historical; page remains live but product is sunset)
+- **Contributing files:** (none)
+- **Status:** `referenced`
+
+## github-docs-marketplace-listing-requirements
+
+- **URL:** https://docs.github.com/en/apps/github-marketplace/creating-apps-for-github-marketplace/requirements-for-listing-an-app
+- **Research doc:** plugins/kyberforge/docs/research/docs/github-copilot-plugins/sources.md
+- **Description:** Requirements for listing a GitHub App on the GitHub Marketplace — verified publisher, capability description, UX stability, submission and review process
+- **Contributing files:** (none)
+- **Status:** `referenced`
diff --git a/plugins/kyberforge/skills/plugin-author/scripts/new-plugin.sh b/plugins/kyberforge/skills/plugin-author/scripts/new-plugin.sh
index 1be5dc4..c078117 100755
--- a/plugins/kyberforge/skills/plugin-author/scripts/new-plugin.sh
+++ b/plugins/kyberforge/skills/plugin-author/scripts/new-plugin.sh
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+# source_keys: github-cli-plugin-reference github-plugins-creating
 set -euo pipefail
 
 usage() {
diff --git a/plugins/kyberforge/skills/plugin-author/tests/README.md b/plugins/kyberforge/skills/plugin-author/tests/README.md
deleted file mode 100644
index 5fa544c..0000000
--- a/plugins/kyberforge/skills/plugin-author/tests/README.md
+++ /dev/null
@@ -1,33 +0,0 @@
-# tests/
-
-Test files for scripts bundled with this skill.
-
-## When to add tests
-
-Add tests here when the skill has scripts in `scripts/` that are complex enough
-to break silently — validators, parsers, generators, anything with branching
-logic or edge cases. Test infrastructure (`.bats`, `*_test.*`, `test_*.sh`)
-belongs here, not in `scripts/`.
-
-## Dependencies
-
-Tests require [bats-support](https://github.com/bats-core/bats-support) and
-[bats-assert](https://github.com/bats-core/bats-assert). The test files load
-helpers from the repo root's `tests/test_helper/`.
-
-From the repo root:
-
-```bash
-git clone https://github.com/bats-core/bats-support tests/test_helper/bats-support
-git clone https://github.com/bats-core/bats-assert tests/test_helper/bats-assert
-```
-
-Run all tests for this skill (from the repo root):
-
-```bash
-bats plugins/kyberforge/skills/plugin-author/tests/
-```
-
-## If no tests are needed
-
-Delete this README and the `tests/` directory entirely.