Skills

A skill is a named, reusable competency an agent can call for a narrow task. A tool does one mechanical thing. A skill does one cognitive thing.

Skills are the right unit when you want a reusable agent behavior without creating a whole new agent.

In This Section

• Creating a skill
• Handler types
• Testing and debugging
• Publishing

When to reach for a skill

• You keep repeating the same prompt pattern across agents.
• One task recurs across projects and needs consistent behavior.
• You want agents composed from named competencies instead of one large prompt.
• You want something lighter than a subagent, but richer than a tool.

Consuming from an agent

async run(ctx, input) {
  return ctx.skills.call("refactor-to-pattern", {
    file: input.file,
    pattern: "adapter",
  });
}

Skill vs. tool vs. subagent

Axis	Tool	Skill	Subagent
Granularity	Atomic operation	Cognitive task	Full task
LLM involved	No	Maybe	Yes
Own reasoning loop	No	No unless implemented that way	Yes
Cost	Low	Low-moderate	High

When in doubt, start with a skill. Promote to a subagent only when separate reasoning state is worth the cost.

See also

• Capabilities
• Agent Blocks
• Subagents