What an Agent Skill actually is
"Skills extend what Claude can do. Create a SKILL.md file with instructions, and Claude adds it to its toolkit. Claude uses skills when relevant, or you can invoke one directly with /skill-name." A skill is created when the same instructions, checklist, or multi-step procedure keep getting pasted into chat, or when a section of a project's CLAUDE.md has grown into a procedure rather than a fact -- unlike that file's content, a skill's body loads only when it's used, so long reference material costs almost nothing until it's needed.
Claude Code skills follow the Agent Skills open standard, which works across multiple AI tools, and Claude Code extends it with invocation control, subagent execution, and dynamic context injection.
The two-part file
Every skill needs a SKILL.md with two parts: YAML frontmatter between --- markers that tells Claude when to use the skill, and markdown content with the instructions Claude follows once the skill runs. The directory name becomes the invoked command (e.g. skills/design-playbook/SKILL.md → /design-playbook), and the description field is what Claude matches against to decide whether to load the skill automatically.
Where skills live
| Location | Path | Applies to |
|---|---|---|
| Enterprise | managed settings | All users in an organization |
| Personal | ~/.claude/skills/<skill-name>/SKILL.md | All of a user's projects |
| Project | .claude/skills/<skill-name>/SKILL.md | That project only |
| Plugin | <plugin>/skills/<skill-name>/SKILL.md | Wherever the plugin is enabled |
Plugin skills use a plugin-name:skill-name namespace, so they cannot conflict with other levels. Every skill this site catalogs is a plugin skill -- cwc-design:design-playbook, cwc-engineering:code-mode-ptc, cwc-product-management:brand-voice, and so on across all of the repo's cwc-* plugins -- which is exactly the shape this table's plugin + name columns preserve.
Source: code.claude.com/docs/en/skills, mirrored locally in this repo's docs/docs/code.claude.com/docs/en/skills.md.