What a Skill is

1A folder with a text file in it

That is not a simplification. A Skill is a directory containing a SKILL.md file, and that file is instructions written in plain English about how you want a job done.

There is no code in the minimum version. There is no build step. You are writing down a procedure, once, in a place something else can read.

Explain-on-first-use: you already met the word in Module 2, where two Skills came with the guide — script-from-intake and claim-guard. This section is what they actually are.

A skill folder can hold more than the one file if you want it to: templates for Claude to fill in, example outputs showing the expected format, reference material. All optional. Start with the text file.

2What it buys you over pasting the same thing every time

Three things.

1. It loads when it's relevant, not when you remember it. Claude reads the description and applies the skill when the work matches. You can also invoke it directly by typing / and its name.

2. Its body costs nothing until it's used. This is the property that makes long reference material practical: the skill's content only enters the conversation when the skill is actually needed. A twelve-page procedure you use twice a month is free the rest of the time.

3. It's a file, so it behaves like one. You can read it, edit it, version it, send it to a collaborator, and tell which version produced which output. Compare that with a procedure that lives in your head, which Module 3 §5 already established is the failure mode this whole system exists to prevent.

3The plan reality — verified 2026-08-14

Better news than most features in this guide.

Skills are available on Free, Pro, Max, Team and Enterprise plans. No paid gate on using or creating them.

One condition: the feature requires code execution to be enabled. Check that before concluding a skill isn't working.

One creation method is gated, and it's the convenience one:

• Recording yourself doing a task and having a skill generated from it is limited availability — Pro, Max and Team, in Cowork on Mac only. Not in chat, not on Windows, not on Free or Enterprise.
• Writing the file yourself works everywhere. That's the method §3 teaches, and it's the one that produces a skill you understand.

Consistent with everything else in this guide: the free path is complete, and the paid extra is a shortcut rather than a capability.

4Two places skills live, and they work differently

This is the part that trips people up, because the same word covers two setups.

If you are a creator rather than a developer, you want the claude.ai path. Write the folder, zip it, upload it, enable it. The Claude Code column is here so that the two Skills shipped with Module 2 — which describe a filesystem install — make sense, and so you know which instructions apply to you.

Watch the 200-character description cap on the claude.ai path. It's the single most common reason an otherwise-fine skill won't upload, and §3 covers how to write within it.

5What a Skill is not

• Not software. Nothing is compiled, nothing runs on your machine because you wrote a SKILL.md.
• Not a plugin. A plugin bundles skills and connectors and is paid-only (Module 2 §7). A skill on its own is neither.
• Not automatic. It doesn't go and do things unattended — that's the agentic surface, Module 2 §6. A skill is standing instructions, applied when the work matches.
• Not a substitute for the intake. A skill holds how you work. Form BV-01 holds what's true about this client. Module 2's skills README is blunt about this: never hardcode one client's guardrails into a skill, because a skill with a client baked into it stops being reusable the moment you have two.

6When one is worth building

The documentation's own test is the best one, and it's short:

Build a skill when you keep pasting the same instructions, checklist or multi-step procedure into a chat.

That's it. Not when the work is complicated — when it repeats. §3 turns that into a recognition test you can run against your own week.