a skill is a directory with a SKILL.md at its root. yaml frontmatter declares the name and description; everything else is free-form.

my-skill/
├── SKILL.md          # required — agent instructions
├── scripts/          # optional — automation helpers
└── references/       # optional — supporting docs

---
name: my-skill
description: A brief description of what this skill does
---

# My Skill

Instructions for the AI agent go here…

• ▸ discovery rosie walks the repo for SKILL.md files — see discovery for the exact algorithm
• ▸ name + description read from frontmatter · used as the install name and shown in rosie list
• ▸ extra files scripts/, references/, anything else in the directory travels with the skill — the agent can use them