At its core, a skill is a folder containing aDocumentation Index
Fetch the complete documentation index at: https://agentskills.skillsdirectory.org/llms.txt
Use this file to discover all available pages before exploring further.
SKILL.md file. This file includes metadata (name and description, at minimum) and instructions that tell an agent how to perform a specific task. Skills can also bundle scripts, templates, and reference materials.
How skills work
Skills use progressive disclosure to manage context efficiently:- Discovery: At startup, agents load only the name and description of each available skill, just enough to know when it might be relevant.
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Activation: When a task matches a skill’s description, the agent reads the full
SKILL.mdinstructions into context. - Execution: The agent follows the instructions, optionally loading referenced files or executing bundled code as needed.
The SKILL.md file
Every skill starts with aSKILL.md file containing YAML frontmatter and Markdown instructions:
SKILL.md:
name: A short identifierdescription: When to use this skill
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Self-documenting: A skill author or user can read a
SKILL.mdand understand what it does, making skills easy to audit and improve. - Extensible: Skills can range in complexity from just text instructions to executable code, assets, and templates.
- Portable: Skills are just files, so they’re easy to edit, version, and share.
Next steps
- View the specification to understand the full format.
- Add skills support to your agent to build a compatible client.
- See example skills on GitHub.
- Read authoring best practices for writing effective skills.
- Use the reference library to validate skills and generate prompt XML.