---
topic: agentskills-overview
source_keys:
  - agentskills-home
  - agentskills-spec
  - agentskills-quickstart
---

## What Agent Skills is

Agent Skills is a lightweight, open format for extending AI agent capabilities with specialized knowledge and workflows. A skill is a folder containing a `SKILL.md` file — metadata plus instructions that tell an agent how to perform a specific task. Skills can also bundle scripts, reference materials, templates, and other resources.

The format was originally developed by Anthropic, released as an open standard, and has been adopted by a large and growing number of agent products: Claude Code, GitHub Copilot, OpenAI Codex, Google Gemini CLI, VS Code, Cursor, JetBrains Junie, Block Goose, OpenHands, Roo Code, Spring AI, Databricks Genie, Snowflake Cortex, and many others — 35+ confirmed implementations as of June 2026.

## Why Agent Skills exist

Agents are increasingly capable but often lack the context to do real work reliably. Skills solve this by packaging procedural knowledge and project-specific context into portable, version-controlled folders that agents load on demand:

- **Domain expertise**: capture specialized knowledge — legal review processes, data pipelines, presentation formats — as reusable instructions and resources.
- **Repeatable workflows**: turn multi-step tasks into consistent, auditable procedures.
- **Cross-product reuse**: build a skill once and use it across any skills-compatible agent.

## Progressive disclosure

Agents load skills in three stages:

1. **Discovery** — at startup, agents load only the `name` and `description` of each available skill (~100 tokens per skill). Just enough to know when one might be relevant.
2. **Activation** — when a task matches a skill's description, the agent reads the full `SKILL.md` body into context (<5000 tokens recommended).
3. **Execution** — the agent follows the instructions, optionally executing bundled scripts or loading referenced files on demand.

Full instructions load only when a task calls for them, so agents can keep many skills on hand with only a small context footprint.

## Canonical directory

The canonical location for skills is `.agents/skills/` at the project root. Tool-specific locations (`.claude/skills/` for Claude Code, `~/.codex/skills/` for Codex) are thin adapters that map to this canonical path. Putting skills at `.agents/skills/` maximizes cross-tool portability.

## File structure

```
skill-name/
├── SKILL.md          # Required: metadata + instructions
├── scripts/          # Optional: executable code
├── references/       # Optional: documentation
├── assets/           # Optional: templates, resources
└── ...               # Any additional files or directories
```

The `SKILL.md` file must contain YAML frontmatter followed by Markdown content. There are no format restrictions on the body.