Guide · AI skills
How to Install AI Skills (SKILL.md) in Claude, ChatGPT, Gemini & Claude Code
Short answer: An AI skill is a folder with a SKILL.md file. In Claude, turn on code execution in Settings, then open Customize → Skills → + → Create skill → Upload a skill and choose the skill’s .zip. In ChatGPT, open Skills → Create → Upload from your computer. In Gemini, paste the skill into a Gem’s instructions. In Claude Code, copy the folder into ~/.claude/skills/.
What a skill actually is
A skill is a small folder that follows the open Agent Skills standard. Inside is a SKILL.md file: a header with a name (lowercase, hyphens, the same as the folder) and a description that says what the skill does and when to use it, followed by the instructions themselves. Optional scripts/, references/ and assets/ folders can sit alongside it.
The description is the part that matters most. The assistant only reads the full instructions when your request matches the description, which is why an installed skill can switch itself on without you pasting anything.
Install a skill in Claude
- Open Settings → Capabilities and switch on Code execution. Skills need it.
- Open Customize → Skills, click +, choose Create skill, then Upload a skill.
- Select the skill’s
.zip. The zip must contain the skill folder at the top, withSKILL.mdinside it. - Switch the skill on — uploaded is not the same as enabled — and start a new chat.
Install a skill in ChatGPT
- Open Skills → Create → Upload from your computer.
- Select the
.zip. ChatGPT scans every uploaded skill; most are ready when the scan finishes. - On business plans an admin may need to allow skill uploads first.
Gemini, Claude Code and other coding agents
- Gemini: open Gems → New Gem, paste the skill’s text into the instructions and save. Chat with that Gem whenever you need the skill.
- Claude Code: unzip the skill into
~/.claude/skills/(all projects) or.claude/skills/inside a project, then restart the session. - Other coding agents: many now read
SKILL.mdfolders; check the tool’s documentation for the folder it scans.
The errors that stop skills working
- “Missing SKILL.md” — the zip has a loose file or an extra nested folder. Zip the folder itself.
- Name mismatch or invalid characters — the
namemust equal the folder name and use onlya-z,0-9and single hyphens. - Installed but never used — switched off, code execution off, or a description without real trigger words.
- Two skills fight over one request — their descriptions overlap; make each one more specific, or name the skill in your message.
Writing a description that triggers
Say what the skill does and list the situations and words that should activate it: “Writes clear, short emails for any situation — requests, follow-ups, replies to difficult messages… Use when the user asks to write, reply to, shorten or improve an email.” Concrete verbs and nouns beat adjectives.
Skip the setup: 40 skills, ready to upload
The AI Skills pack includes 40 skills with upload-ready .zip files — writing, research, business, marketing, productivity and code — plus the skill-builder and skill-auditor skills, 50 prompts and a weekend project for building your own library. Every other AI Prompt & Skills pack now ships its skills in the same installable format.
AI Prompt & Skills is an educational toolkit; the AI tools mentioned are third-party and not affiliated with AI Prompt & Skills. Your results depend on your own effort.
Frequently asked questions
What is a SKILL.md file?
It is the file at the heart of an Agent Skill. It starts with a short header containing the skill's name and a description of what it does and when to use it, followed by the instructions. The assistant reads the description to decide when to load the skill.
Why does my skill upload fail?
Usually because the zip does not have the skill folder at its top level, or because the name in the file does not match the folder name or uses capitals, spaces or underscores. Names must be lowercase letters, numbers and single hyphens.
My skill is installed but never used. Why?
Check that it is switched on, that code execution is on in Claude, and that the description contains the words people actually use when they need it. A vague description is the most common reason a skill never triggers.
Do skills work in Gemini?
You can paste a skill's instructions into a Gem and chat with that Gem. Some Gemini versions can also import skill files directly where that option is shown.
Are third-party skills safe to install?
Read the SKILL.md first and any scripts in its scripts folder. Never install a skill that asks for passwords, API keys or private data, and prefer skills from sources you trust.