Closes #5. Single authoring skill replaces the factory trio — one set of standards, one script, one place for future governance rules. Routes to create or improve flow based on context. Passes skill-audit with no findings. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016z2ZFYHQCex8yZAMVMTZzZ
11 KiB
name, description, allowed-tools, metadata
| name | description | allowed-tools | metadata | ||
|---|---|---|---|---|---|
| skill-author | Use when the user wants to create a new skill from scratch ("write a skill for X", "build a skill that does Y", "create a SKILL.md for Z"), or improve an existing one ("improve this skill", "fix based on feedback", "apply these audit findings", "update based on grill output"). Also use when the user provides inline feedback about a skill's behavior and wants it applied, or when a grill session, eval run, or audit has produced findings the user wants acted on — even if they don't say "improve" explicitly. Authors and refines skills following the agentskills.io specification. Performs best when preceded by a grill session and domain research. Do not use for read-only review — use /skill-audit instead. Do not use to author agent definition files. | Bash Read Write Edit |
|
Gotchas
- Patching per symptom is the default failure mode. Three eval failures may all trace to one missing instruction — always identify the root cause before editing.
- Do not create new scripts unless a signal explicitly calls for it. Writing scripts from scratch requires transcript analysis that is out of scope here; flag the opportunity as a suggestion instead.
Route
Determine which flow to follow before touching the filesystem:
- No skill directory at the target path → follow Creating a new skill
- Directory exists + at least one improvement signal present → follow Improving an existing skill
- Directory exists + no signals present → ask: "No improvement signals found. Did you mean to create a new skill, or do you have feedback to apply?"
Signals include: grill session output, /skill-audit findings (PASS/FAIL punch list), inline user feedback, session context describing what went wrong.
Creating a new skill
Prerequisites
Run /grill-me on the skill's design and research the target domain first.
Share those outputs in this conversation: grill context, research docs, examples, constraints.
Before touching the filesystem, verify you have:
- A clear purpose — what specific task will this skill handle?
- Trigger scenarios — when should an agent activate it, including indirect cases?
- Skill name (kebab-case) and destination path
If any are missing, stop and ask the user before proceeding.
Requires /skill-audit — used in Step 5 for final validation. Both skills ship in the kyberforge plugin and are co-installed. If /skill-audit is unavailable, stop and ask the user to install the kyberforge plugin before continuing.
Step 1 — Scaffold
Run the copy script with the skill name and destination directory:
bash scripts/new-skill.sh <skill-name> <destination-dir>
Examples:
bash scripts/new-skill.sh my-tool ~/.agents/skills/
bash scripts/new-skill.sh data-analyzer plugins/myplugin/skills/
This creates <destination-dir>/<skill-name>/ with annotated templates ready to fill in.
If the destination is inside a plugin directory (path contains a plugin.json), read references/deployment-modes.md before adding any file references to SKILL.md.
Step 2 — Fill in SKILL.md
Open <destination-dir>/<skill-name>/SKILL.md. Replace every FILL IN: placeholder.
Frontmatter
name — already set by the scaffold script. Must exactly match the directory name.
description — carries the entire triggering burden. Rules:
- Imperative: "Use when..." not "This skill..."
- Focus on user intent, not implementation — describe what the user is trying to achieve, not the skill's internal mechanics
- Specific about capabilities ("parses and validates OpenAPI specs", not "helps with APIs")
- Include indirect triggers: "even if the user doesn't mention X explicitly"
- Add "Do not use when..." only if a near-miss skill exists that could steal activations
- Hard limit: 1024 characters — count before finalizing
Optional fields — uncomment and fill in or remove entirely:
license— include when distributing the skill externallycompatibility— include if the skill requires specific tools, runtimes, or network accessmetadata— key-value map; useauthor,version,categoryallowed-tools— space-separated pre-approved tools; reduces permission prompts
Body — include only what the agent lacks
Rename the placeholder section heading to one that fits the skill's structure — ## Step 1, ## Workflow, ## Instructions, etc.
Ask of every sentence: "Would the agent get this wrong without it?" Cut anything that answers "no."
Include:
- Non-obvious sequences or ordering constraints — the agent may skip or reorder steps without this
- Domain conventions the agent cannot infer from general knowledge — this is the core value a skill adds
- One default per decision point, plus one escape hatch — never a menu; menus cause the agent to pause or pick arbitrarily
- Gotchas — facts that defy reasonable assumptions; the agent will get these wrong every time without them
Exclude:
- Concepts the agent already knows (what JSON is, how HTTP works) — adds tokens without changing behavior
- Exhaustive option lists — pick a default; the agent doesn't benefit from choosing
- Steps the agent handles independently — over-specifying leads agents to follow unproductive paths
- Restatements of the description — it's already in context; repeating it wastes the token budget
Patterns
Gotchas — highest value; place near the top:
## Gotchas
- <Fact that defies a reasonable assumption>
- <Non-obvious naming discrepancy or hidden constraint>
Default with escape hatch (not a menu):
Use <X> for <task>. For <edge case>, use <Y> instead.
Prescriptive sequence (when order is critical or fragile):
Run exactly:
\`\`\`bash
<command>
\`\`\`
Do not modify flags.
Checklist (multi-step workflows):
- [ ] Step 1: ...
- [ ] Step 2: ...
Conditional reference (progressive disclosure — load only when needed):
If <condition>, read `references/<file>.md`.
Size budget
Keep SKILL.md under 500 lines and 5,000 tokens. When approaching the limit:
- Move reference material to
references/<topic>.mdand load it conditionally - Bundle repeated executable logic into
scripts/rather than reinventing each run
Step 3 — Add scripts (if needed)
Place executable scripts in scripts/. Rules for agentic scripts:
- Self-contained — bundle dependencies inline so the agent can run the script with a single command; do not require a separate install step
- No interactive prompts — agents run non-interactive; blocking on TTY input hangs indefinitely. Accept all input via flags, env vars, or stdin.
- Expose
--help— concise usage output; keep it short (it enters the agent's context) - Structured output — data (JSON, CSV) to stdout; diagnostics and progress to stderr
- Idempotent — "create if not exists"; agents may retry on failure
- Meaningful exit codes —
0success, non-zero failure; document in--help - Dry-run support — add
--dry-runfor destructive operations
If the skill needs scripts with external package dependencies or language-specific tooling (Python, TypeScript, Ruby, Go), read references/scripts.md for package runner patterns and inline dependency formats.
If no scripts are needed, delete scripts/README.md and the scripts/ directory.
Step 4 — Add references, assets, and tests (if needed)
references/ — additional documentation loaded on demand. One topic per file.
Reference conditionally from SKILL.md: If <condition>, read references/<file>.md.
assets/ — static resources: templates, schemas, lookup tables.
Reference by relative path from SKILL.md.
tests/ — test files for scripts in scripts/. Use when scripts are complex
enough to break silently. Test infrastructure (.bats, *_test.*) belongs here,
not in scripts/. See tests/README.md for setup instructions.
If not needed, delete the placeholder READMEs and their directories.
Step 5 — Validate
Run /skill-audit on <destination-dir>/<skill-name>.
All FAIL findings must be resolved before the skill is considered done.
Improving an existing skill
Step 1 — Verify inputs
Confirm the skill directory path exists and that at least one improvement signal is present in the conversation or a referenced file.
If the skill dir is missing, ask for it. If no signals are present, stop: "This skill applies existing signals to a skill. For a blind review without signals, use /skill-audit instead."
Signals can come from anywhere in the conversation or referenced files:
- Grill session output (most common predecessor in the factory sequence)
/skill-auditfindings (PASS/FAIL/SUGGESTION punch list)- Human feedback (feedback.json, inline in conversation, PR or issue comments)
- Session context describing what went wrong
Step 2 — Gather and group signals
Read the current skill files (SKILL.md and any files in scripts/, references/, assets/, tests/). Then collect all signals from the conversation and any file paths the user has referenced.
Group signals by root cause, not symptom. Ask: "What single gap in the skill causes this cluster of failures?" One root cause → one fix. Do not make a separate edit for each symptom.
Example:
- Session context: output format is wrong on every run
- Audit finding: no output template defined
- User feedback: "I always have to ask it to format the output"
→ Root cause: SKILL.md has no output format specification → one fix: add an output template
Step 3 — Announce planned changes
Before editing, state:
- Which root causes were identified and what evidence supports each
- Which files will be changed and what will change in each
Then proceed — edits are reversible via git, no approval checkpoint needed.
Step 4 — Apply changes
Edit any file in the skill directory that the signals point to: SKILL.md, scripts/, references/, assets/, tests/, README.md.
Generalize, don't patch. Find the underlying gap, not the specific example that failed. A fix scoped only to the test cases you've seen will overfit and perform worse on new inputs.
Keep it lean. Remove instructions that aren't pulling their weight. For every sentence you add, ask: "Would the agent get this wrong without it?" A shorter, focused skill consistently outperforms an exhaustive one.
Explain the why. Reasoning-based instructions outperform rigid directives. If you find yourself writing a rule in all caps (ALWAYS/NEVER), reframe it: explain why the behavior matters so the agent can apply judgment in edge cases.
If a signal points to a script or reference file, edit that file directly rather than adding a workaround in SKILL.md.
On scripts: Fix and edit existing scripts freely when signals point to them.
Step 5 — Validate
Run /skill-audit on the skill directory. Resolve any FAIL findings before considering the improvement complete.