What a CLI skill is
A Gemini CLI skill is the terminal-side face of the same SKILL.md format the rest of the family adopted — a directory holding a SKILL.md that teaches the agent a repeatable job: how to run a release, how to write a migration note, how to scaffold a service in your house style. When the agent's task matches the skill's description, the file loads into context and steers the run.
This is the format that absorbed two earlier mechanisms. In the consumer Gemini app, skills replaced Gems; inside Antigravity they replaced workflows. In the CLI they arrived as part of the same family-wide standard, which is what makes a well-written skill portable — the same SKILL.md can steer the terminal agent, the IDE agent, and (with format caveats) agents in other ecosystems that adopted the standard.
How to evaluate a skill before you install it
- Read the description line like a search keyword. Skills trigger on their description — a vague one ("helps with code") either fires constantly or never; a precise one ("draft a changelog from merged commits since the last tag") fires when it should.
- Check for procedure, not personality. A useful skill is a numbered sequence with decision points; a page of tone instructions produces inconsistent output.
- Look at what it assumes. Skills that reference paths, tools or CLIs need those to exist — the good ones check and say what to do when they don't.
- Prefer skills that version themselves. The format is young; a skill that records which CLI version it was written against is easier to trust after the next release.
Where skills live
The same skills/<name>/SKILL.md convention appears in the CLI workspace, in Antigravity projects, and in the consumer app's library. Entries on this page are CLI-tested — a skill that works in the terminal but assumes IDE-only features gets a caution note saying where the boundary is.
If you are coming from Antigravity workflows: this is where that ecosystem went. The skills hub inherits the workflow idea — a saved procedure, invoked as a unit — in a format that also travels to other tools. Skills listed here are checked for whether their procedure actually survives a terminal context: no IDE panels, no editor state, just the shell. For skills authored elsewhere, check the caution notes — the port is usually trivial but never assumed. Entries note which CLI version each skill was last verified against.