When Skills Don't Trigger (and How to Fix Them)

You spend twenty minutes writing a skill: the exact checklist you keep pasting into Cowork for how you want release notes formatted. You save the SKILL.md file, ask Cowork to draft the notes, and watch it produce something generic. The skill you just wrote sat there untouched.

There's no error. No "skill not found." Cowork just answered the way it would have if the skill didn't exist, and unless you knew to check, you'd never notice it was skipped. A broken script throws; a skill that doesn't trigger says nothing.

The skill isn't broken. Cowork didn't read it and reject it; it never picked it up in the first place. And the part that decides whether it gets picked up is the one part most people write last and least.

#The description is the trigger

A skill is two things: a description and a body. The body is your instructions: the checklist, the format, the steps. But Cowork doesn't read the body to decide whether a skill applies. It reads the description.