Create, audit, and refactor portable agent skills (`SKILL.md`). Use when asked to "create a skill", "review a skill", "improve a skill", "author a skill", "refactor a skill", "compare skill rubrics", "distill a skill from sessions", "reconcile skill plans", or "teach skill authoring"; when paths include `skills/<name>/SKILL.md`, `references/*.md`, helper scripts, evals, lockfiles, security manifests, or vendor adapters; or when mentions include skill-creator, Skill Development, skills.sh, trigger descriptions, progressive disclosure, skill evals, completion criteria, leading words, repository gates, or model/user invocation.