Build your first Claude skill with skill-creator

Pick the job your team did most last week. Good first candidates for a skill:

• The first draft of a proposal
• A meeting recap with owners
• A content brief
• A new-client onboarding checklist
• The reply to a late invoice

Each one has the same steps, the same checks and the same format every time. That is what a skill holds. Start with one skill, not five.

Choosing between two candidates

If two jobs tie, ask three questions about each. Did it happen at least twice last month? Can you point to one past result you are proud of? Could a new hire do it from a checklist? Pick the job with the most yes answers. A job that changes shape every time, like a one-off negotiation, is a poor first skill, because there is no steady pattern to save.

Check claude.ai first. Open Customize > Skills and look for skill-creator in the list. If it is there, switch it on and skip the rest of this section. The GitHub and plugin route below is for Claude Code. If you use claude.ai and cannot find it, see Anthropic's skills page.

skill-creator lives in Anthropic's public skills repository on GitHub, in the skill-creator folder.

In Claude Code, the repository README gives this line to add the skills collection: /plugin marketplace add anthropics/skills. Confirm it on the README before you run it, because commands can change.

skill-creator works best when it sees real work. Collect two things:

1. 1

   Your best past example of the job, done well.

2. 2

   Your checklist. What a good result must include and what it must never do.

Remove client names and private details from the example before you paste it.

Write the checklist as plain rules, in your own words. "Always name an owner for every action" is better than "be clear". If you have no checklist yet, write down what you check before you send the work to a client. That list is your checklist.

Ask Claude to use skill-creator, then paste this.

Answer the questions in plain words. It asks for what you do, then writes the skill and tests it. When it asks for the two test examples, paste two real ones from your own work.

A worked example

Picture a six-person bookkeeping firm. Every month, the owner sends clients a short recap of what was done and what the client still owes the firm: missing receipts, unsigned forms, questions about odd entries. Last month's recap took her 40 minutes, and each team member wrote theirs a little differently.

She picks "the monthly client recap" as the job. She pastes her best recap from last month, with the client's name removed, and her checklist: open with one sentence on the overall state, list open items with an owner and a due date, never guess at a figure, end with the next step.

skill-creator then asks questions one at a time. It might ask what she starts with before writing a recap. She answers: the open items from the task board and her notes from the last call. It might ask what a recap must never contain. She answers: anything about the firm's own internal problems, and no promised dates unless a person has agreed to them. Those answers become rules in the skill.

When the skill is written, Claude asks for two test examples. She gives it two real months of notes from two different clients. In the first test, the recap leaves out due dates. She tells Claude, it changes the skill, and the second test includes them. She then packages and installs the skill, opens a new chat, and runs it on the current month. The draft opens with one line on the state of the books, then lists two open items, each with an owner and a due date. Instead of writing from a blank page, she now edits a draft, and every recap follows the same checklist.

The skill did not make the judgment calls. She still reads every recap before it goes out.

A skill Claude has written is not yet a skill you can use. Install it.

1. 1

   Ask Claude: "Package this skill as a ZIP file of the skill folder. The folder name must match the skill name." Download the ZIP.

2. 2

   In Claude, open Customize > Skills. Click the + button, click + Create skill, choose Upload a skill, and pick your ZIP. The skill appears in your list with a switch to turn it on or off.

3. 3

   Start a new chat and run the job. Do not test in the chat where you built it, because that chat already knows everything you told it.

4. 4

   Check that Claude used the skill. If it did not, ask where the skill went wrong, then fix and reinstall.

The last step is the one people skip. Run the skill on next week's real job, and fix what it gets wrong.

Check its first three outputs yourself before a client sees one. If you want a fuller test, use the five-input check in test a Claude skill before client work.

Why this works: Claude follows instructions literally, and it only knows your process from what you tell it. A skill puts your steps and your standards in one place, so you stop re-explaining them each time. It cannot tell when your standards have changed, so you still need to review its output.

Common mistakes

1. 1

   Building a skill for a job you do once a year. You will not run it enough to learn what is wrong with it. Pick a job that comes up weekly.

2. 2

   Pasting an average example. Claude copies what you give it. Paste your best work, not the most recent work.

3. 3

   Testing with tidy or matching examples. Easy cases hide problems. Use two real inputs that differ, such as a quiet month and a messy one.

4. 4

   Never updating it. When a client asks for something new or your process changes, tell Claude what changed and reinstall the skill.

When something fails, change one thing at a time. If you change the example, the checklist and the description together, you will not know which change fixed it. After each fix, rerun the same test input and compare the two results side by side.