Simple explanation
A skill is a saved set of instructions for one task: how to review a page, how to write a release note, how to check a form before launch. Instead of retyping a long prompt, you call the skill and the AI follows the same steps every time.
Google is replacing Gemini Gems with skills, and the rollout is reaching more accounts this month. Gemini skills can be created by uploading a SKILL.md file, the format Anthropic created and published as an open standard in December 2025. ChatGPT, OpenAI's Codex and many coding tools support the same format.
That changes the value of your prompts. A good prompt used to be locked inside one tool. A skill written in the shared format can travel with you when you switch tools, or when the model you use changes.
The same week also showed the other side. Anthropic launched Claude Code mods, small add-ons that can rewrite prompts, approve or deny permission requests and change how the agent works. Mods are not sandboxed: they run with the same access to your computer as Claude Code itself. Skills and add-ons are powerful because they shape what the AI does, and that is exactly why you should know where they came from.
What to do
Turn your three most-used prompts into skills you own:
1. List the prompts you retype most often. Good candidates are review checklists, launch checks, bug reports and "explain this error" requests.2. Pick one and rewrite it as one task: a short name, one sentence saying when to use it, and step-by-step instructions.3. Save it as a SKILL.md file in your project folder or a private repository, so you have one master copy you control.4. Test it on a real example in the tool you use today. Fix the instructions until the result is consistent.5. Keep secrets out. No passwords, API keys or customer data in a skill; add those details in the chat when needed.6. Only install skills, plugins or mods from sources you trust, and read what they do first. If an add-on can approve permissions or edit prompts, treat it like software you are installing, because that is what it is.
If you use Gemini Gems today, start with the Mini Tutorial "Moving From Gemini Gems to Skills" before the switch reaches your account.
Copy-paste prompt
Here is a prompt I use often: [PASTE PROMPT]. Turn it into a reusable skill in the SKILL.md format. Give me: 1. a short name; 2. a one-sentence description of exactly when to use it; 3. clear step-by-step instructions, including the output format I want. Keep it to ONE task. Do not include passwords, API keys or private customer data; write [ADD DETAILS HERE] where I need to add specifics each time. Finish with one test request I can use to check the skill works.
Course note
Key takeaway
Your best prompts are now portable. Save them as skills you own, keep secrets out of them, and only install add-ons you trust.