AI agent glossary
Agent skills
Reusable folders of instructions, scripts, and reference files that an agent loads only when a task calls for them.
A skill packages know-how for a specific kind of task: how to produce your team's weekly report, how to fill in a particular PDF form, how to follow your release checklist. Each skill usually lives in a folder with a main instructions file, often named SKILL.md, plus any supporting scripts or examples.
The key idea is loading on demand. The agent sees only a short name and description for each skill up front. When a task matches, it reads the full instructions. This keeps the context window small while still giving the agent access to a large library of expertise.
Skills are supported by Claude Code, the Claude apps, and the Claude Agent SDK, and the format has been published as an open standard, Agent Skills (agentskills.io), that other tools can adopt. They work best for procedures you find yourself explaining to an agent again and again.
A changelog skill tells the agent how to read recent commits, group them by type, and write release notes in your house style, and includes a script that lists merged pull requests.
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