Agent Skills (the format)
Open standard for agent skillsOpen standard
A skill is a folder with a SKILL.md file — a name, a description, and instructions — plus optional scripts and reference docs. The agent sees only the short description until a task needs the skill, then loads the rest. Published by Anthropic as an open standard in December 2025.
Official siteReach for it when
- Packaging a repeatable workflow once and using it across agents
- Understanding what the skills in this group actually are
Worth knowing
Skills are instructions and scripts loaded into the agent's context. They don't retrain the model or give it persistent memory.