Agent Skills

Agent Skills – modules of knowledge loaded on demand, instead of bloating the system prompt.

Three levels of progressive disclosure:

1. metadata – name + description of all Skills constantly in context (hundreds of tokens);
2. main SKILL.md – loaded when the model decides a Skill is needed;
3. subdocuments and scripts – by link as needed.

Description should be a routing condition (“when to use”) with counterexamples.

Skills provide a stable path for accumulating domain knowledge.

Related: Agent State String, Proactive Tool Discovery, Specialized Tool vs Skill