Skill builder
Create a SKILL.md with front matter and instructions for an agent skill.
Runs in this tab. The file stays here.
This runs in your browser. Nothing is uploaded.
About Skill builder
Create a SKILL.md with front matter and numbered steps for an agent skill. Generated in your browser.
A skill is a folder with a SKILL.md file inside: a name and a description in front matter, followed by instructions the agent reads when the skill applies. The description is the part that decides whether the skill is ever used, because it's what the agent sees when choosing, so the form puts it first. Fill in a name, a description, the situations it applies to, the steps, and any notes.
The page tidies the input as it goes. The name is lower-cased and turned into a hyphenated slug of at most 64 characters, so "PDF Form Filler" becomes pdf-form-filler. The description is collapsed onto one line and quoted in the front matter. When-to-use and notes become bullet lists, and the steps are numbered in the order you wrote them. Empty sections are left out, and a blank name falls back to my-skill.
It writes the file text and nothing else: you make the folder, save the file, and add any scripts or reference files yourself. Where the folder goes depends on the agent; each product has its own skills directory. A good skill is short and says exactly when to trigger, so spend your effort on the description and cut anything the agent would do without being told.
How to use Skill builder
- 1Enter a skill name and a description that says what it does and when to use it.
- 2List when to use it, one situation per line, and write the steps one per line.
- 3Add notes if there are caveats.
- 4Copy or download SKILL.md and save it in its own folder.
What it won't do
- Generates the SKILL.md text only; no folder, scripts, or validation.
- Fixed layout: front matter, When to use, Steps, Notes.
- Nothing is saved between visits.
Common questions
Which folder does SKILL.md go in?
In its own folder inside your agent's skills directory, with the file named SKILL.md. The path differs between tools, so check the one you use.
Why did my name change?
Names are converted to lowercase with hyphens, and cut to 64 characters, so they work as folder names. The heading in the file keeps the name as you typed it.
What makes a good description?
One or two sentences about what the skill does and the situations that should trigger it, written in terms of the user's request. The agent matches against it, so vague descriptions mean the skill never fires, and over-broad ones mean it fires when it shouldn't.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation