Cookbook
Agents & skills · for AI agents

Author a load-on-demand skill

Package a capability the model pulls only when relevant — create it and attach it to an agent.

MCP tools:list_skillscreate_skillupdate_agent

Principle — keep the skill count small. Attach only what this agent's job needs (≈5 or fewer). The model picks skills from their one-line description; the more you attach, the more often it loads the wrong one or none. If two skills overlap in when, merge them. More in Design principles.

A skill is a capability pack loaded on demand: the system prompt carries only its description ("when to use"); the model pulls the full instructions only when it judges the skill relevant. So the description must be short and say when, or the model won't know to reach for it.

list_skills()                                # what already exists
 
create_skill(
  name="refund-policy",
  description="Use when the user asks about refunds, cancellations or chargebacks.",
  instructions="The full procedure: eligibility windows, how to word the outcome, when to escalate …",
)
 
update_agent(name="Support", skills=["refund-policy"])   # attach it

Keep procedures in instructions (fetched on load), not in the agent's soul (which is in the prompt every turn). A one-line description that says when is what makes the skill discoverable — a vague one means the model never pulls it.