SKILL.md Format

Each skill is a directory containing one SKILL.md. Its frontmatter supplies catalog metadata; the remaining Markdown is the body returned by the Skill tool.

Document shape

---
name: weather-briefing
description: Turn weather observations into a practical recommendation.
---
Use the weather lookup tool before answering.

1. State the city, temperature, and conditions.
2. Give one practical recommendation.
3. Do not invent measurements.

The directory name and frontmatter name must match. Names are validated before a path is constructed. description is the short catalog text the model sees before it loads the body.

Writing guidelines

• State when to use the skill and when not to use it.
• Name tools by their model-facing names.
• Describe required evidence and output shape.
• Keep credentials, tokens, and environment-specific secrets out of the file.
• Prefer steps and small examples over a second system prompt.

skills/
└── weather-briefing/
    └── SKILL.md

Source and proof

• Skill parser and metadata types
• Parser tests