I adopted skills quite late, but the timing turned out to be right. Skills now work in Droid, Claude Code, and Codex — so I can write them once and use them across all 3 agents.

I wrote about my shared agent setup previously. Skills fit right into that — they live in the same shared directory, softlinked so all agents pick them up.

What Skills Are

Skills are small markdown files with a name, description, and a prompt. When you tell the agent to do something that matches a skill’s description, it picks up the skill and follows the instructions. Think of them as reusable slash commands that the agent can call.

Here’s a simple one I use for committing:

---
name: commit-succinct
description: Commit code succinctly. When user says "commit"
  or "git commit"
---

Commit the dirty changes with a short, succinct message.

In practice, the agent doesn’t always pick up the right skill — or any skill at all — especially when triggered by single, common words like “commit”. So I mention in my AGENTS.md that when I say “commit”, it should use the commit-succinct skill. With that hint, it works reliably — I just say “commit” and it stages changes, writes a concise message, and commits.

Why They Click

Before skills, I’d either type the same instructions repeatedly or rely on custom commands (which work differently across agents). Skills are just markdown files with a standard format that all 3 agents understand.

A skill can also call another skill. I have a “review+fix” skill that calls a “review dirty” skill in a loop — Codex reviews the changes, Droid fixes what’s flagged, repeat until clean. I’ll write more about that next.

This makes it easy to build up complex workflows from simple pieces. “Review+fix, commit, deploy when good” — and the agent knows what each of those steps means because each one is a skill.

When You Don’t Need Them

Sometimes you need to test something carefully, sometimes you don’t. Skills aren’t about automating everything — they’re about not repeating yourself for the patterns you’ve already figured out. The agent still needs your judgment for the hard parts.