Why Your Claude Code Custom Skills Fail to Trigger and How to Fix Them

A development team manager who has used Claude Code daily for months found that custom skills — built to automate tasks like code review and debugging — often fail to activate not because of flawed instructions, but because of poorly written descriptions. In Claude Code, a skill's description acts as a routing rule, and the full instructions only load after the description matches a user's request. The author found that descriptions must include the casual, abbreviated phrases developers actually type — such as 'review this' or 'fix it' — rather than formal language. He also recommends specifying the types of inputs that trigger a skill, such as pasted code or stack traces, and defining clear boundaries to prevent overlapping skills from conflicting. His practical test: make five natural, real-world requests in a fresh session and only ship the skill if it fires on at least four of them.