This is the meta-skill for building skills themselves. Use it when you're creating new Claude Code skills, organizing skill contents, or need guidance on what goes in SKILL.md versus references versus assets. It walks through the progressive disclosure model (metadata, then SKILL.md, then bundled resources) and provides a structured creation process: understand concrete usage examples, plan reusable contents, then build the structure. The most useful part is the analysis framework for deciding what belongs in scripts (deterministic code you'd rewrite), references (docs Claude needs to read), and assets (files used in output). If you're building plugins with custom skills, this teaches the architecture.
npx skills add https://github.com/aiskillstore/marketplace --skill skill-development