What a Skill actually is
A folder with a SKILL.md in it. That is the entire format. YAML frontmatter with a name and a description, then markdown instructions.
---
name: my-skill-name
description: What this does and when to use it
---
# My Skill Name
[instructions Claude follows when this skill is active]
Claude loads a skill only when the description matches what you are doing, so it costs nothing until it is useful. That is the difference between this and a giant system prompt that you pay for on every single message.
The install, one line
/plugin marketplace add anthropics/skills
Then either browse and install, or go straight at the two plugins:
Free, for your email
Get the full setup steps + the copy-paste setup prompt
The rest of this guide (2 more sections) opens right here. The setup prompt, one paste into Claude that sets it all up, comes by email only. Use your real address.
Unlocks: /plugin install document-skills@anthropic-agent-skills · /plugin install example-skills@anthropic-agent-skills
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