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What are Claude skills, and how to use them in Claude, ChatGPT and Gemini

A plain-English guide to agent skills: what a SKILL.md is, how to add skills to Claude and Claude Code, and how to reuse the same skills in ChatGPT, Gemini and Cursor.

What is a skill?

A skill is a folder with a SKILL.md file in it. The file starts with a short name and description, followed by step-by-step instructions that teach an AI agent how to do one job well — for example, filling in a PDF form, writing release notes in your house style, or reviewing a pull request. A skill can also include helper scripts or reference files.

Anthropic introduced skills for Claude. The agent reads only the short description until a task needs the skill, then loads the full instructions. That keeps conversations fast while giving the agent deep know-how on demand.

Skills vs. MCP servers vs. prompts

  • Skill — instructions (and optional scripts) that teach how to do a task.
  • MCP server — a connector that gives the agent new tools, like reading GitHub or querying a database.
  • Prompt — a one-off message you paste into a chat.

They work well together: an MCP server gives access, and a skill explains how to use it properly.

How to use skills in Claude

  • Claude apps (claude.ai): turn on skills in Settings, then upload a skill folder as a ZIP.
  • Claude Code: put the skill folder in ~/.claude/skills/ (for all projects) or .claude/skills/ inside a project. Claude Code finds it automatically.

How to use the same skill in ChatGPT, Gemini or Cursor

A SKILL.md is just text, so other assistants can follow it too:

  • ChatGPT: paste the skill's instructions into a Custom GPT's instructions, or into a Project's instructions.
  • Gemini: create a Gem and paste the instructions in.
  • Cursor and other coding agents: save the instructions as a rule file (for example in .cursor/rules/) or add them to AGENTS.md.

Every skill page in this directory has Copy and Download buttons for exactly this.

Let your agent find skills for you

Connect the AI Skill Directory MCP server (https://aiskilldir.com/mcp) and your agent can search the directory and fetch a skill's full instructions on its own. See Connect your agent for setup steps.

Where to start

Browse agent skills, MCP servers or agent rules — or read how to check a skill is safe before installing one.