skill-mcp

The example skill shipped with skill-mcp — shows the SKILL.md shape, a bundled reference file, and a declared runnable script.

skill-mcp demo

This skill exists so skill-mcp does something useful the first time it runs, and so the shape of a skill it can serve is visible in one file.

What a skill is

A directory holding SKILL.md — YAML frontmatter (name, description, and optionally the mcp-host: block below) followed by instructions — plus any files the instructions refer to. Read references/declaration.md with skill_file for the declaration block's fields.

Declaring a runnable script

Only a script named in mcp-host.run may be executed, and only through skill_run. This skill declares one:

• scripts/report.js — prints what the fence handed it: its argv, its working directory, and the NAMES of the environment variables it received.

Run it to see the fence from the inside:

text

skill_run(name: "skill-mcp-demo", script: "scripts/report.js", args: ["hello"], confirm: true)

What the fence does and does not do

It decides which code runs and what it is handed. It does not make the code safe — a declared script is still arbitrary code, bounded by whatever the host running this server bounds it with.