What Are Claude Skills?

Short definition

A Claude Skill is a portable folder that teaches Claude how to perform a specialized task in a repeatable way. The front door is a SKILL.md file with metadata and instructions; optional subfolders can hold scripts, references, templates, and assets that the agent reads only when the task calls for them.

The most useful mental model is "a small operating manual plus optional tools." A skill is not just a prompt snippet, because it can carry files and executable helpers. It is also not a remote service, because the core unit is a local or uploaded package that the agent can inspect.

Why Skills exist

General instructions are brittle when the task has many steps, special file formats, house style rules, or repeated quality checks. Skills let a team put that procedure in one named package, so a future agent run can load the same guidance without forcing the user to paste a long prompt every time.

This is especially valuable for document conversion, brand-guideline work, visual design workflows, internal communications, API usage patterns, and other tasks where "do the job our way" matters as much as the raw model capability.

Where they run

Claude Code supports skills from three broad locations: project skills in .claude/skills, personal skills in ~/.claude/skills, and plugin-distributed skills from installed marketplaces. Claude.ai exposes Anthropic-managed skills and custom skills through the app for eligible plans. The Claude API exposes skills as uploadable packages for Messages API workflows.

That means the same concept spans several product surfaces, but you should still read the current docs for the surface you are using. Claude Code path rules are not the same thing as Claude.ai upload rules, and API packaging has its own lifecycle.

What a Skill is not

A skill is not an MCP server. MCP connects Claude to external tools and data sources through a protocol. A skill can explain how to use a tool, or include a script, but it does not turn into a live connector just because it exists.

A skill is not a complete product integration by itself. It can encode a workflow, provide templates, and run bundled helpers, but credentials, permissions, network access, and external systems still need ordinary engineering review.

FAQ