What a Claude Skill actually is
The core of a Skill is a folder with a SKILL.md file. That file describes when the Skill should be used, what steps the agent should follow, what output it should produce and where the boundaries are. A Skill can also include reference files, templates, scripts and examples.
The practical difference is reuse. A prompt is written for one conversation. A Skill is written for a class of tasks, so the agent can use the same method tomorrow, in a different project, without you reconstructing the instructions from memory.
What belongs inside a good Skill
The strongest Skills are narrow and explicit. They read more like an operating procedure than a motivational brief:
- A trigger description that says when the Skill should activate.
- Ordered steps with checkpoints, so the agent does not skip the hard part.
- A defined output: a brief, a report, a component, a video plan or a review.
- One or two examples of good work, plus the rules that make the output acceptable.
- Explicit boundaries: what the Skill must not do, when it should stop and what it should ask for.
Claude Skills vs a prompt
A prompt is a message. A Skill is a package. If you are asking for a one-off rewrite or a quick brainstorm, a prompt is usually enough. If you keep giving the same instructions with the same quality bar, a Skill removes the repetition and makes the result more consistent.
This is also why Skills are easier to hand to a team. The method lives in a file that can be reviewed, versioned and improved instead of disappearing into a chat history.
Where Claude Skills run
Skills are used by agent clients such as Claude Agent, Codex, OpenClaw and Hermes. The exact installation path depends on the client, but the object is the same: a folder with instructions the agent can discover and load.
Capafy AI takes a different route for people who do not want to configure a local client. Agents are published as ready-to-run Skills in the browser: sign in with Google, open the agent page and press Run. No terminal, no package manager and no local setup.
How to try a Claude Skill without building one
Browse the agent-skills examples or open a category that matches your work. Read the description to see what the Skill is designed to produce, then compare its price, rating and sales count with neighbouring agents. Free agents and free trials are the lowest-risk way to see the format in action.
If you want to understand the mechanics before buying anything, read the plain-English guide to agent skills and the step-by-step SKILL.md guide. Then come back to the marketplace and compare what a well-packaged Skill looks like when it has real buyers.
Building your own
Start with one job you already do repeatedly. Write the trigger, the steps, the output and the boundaries. Add examples of good and bad work. Test it against real inputs before you publish it.
On Capafy, publishers keep 80% of every sale while the marketplace handles payments and the runtime. That makes the marketplace a practical place to turn a private Claude Skill into a product without building a checkout and hosting stack first.
Updated October 2026. Facts checked against the live Capafy AI marketplace.
