SKILL.md checker
Paste the content of a SKILL.md: the header, name and description are checked against the Agent Skills standard. Everything happens in your browser, nothing is sent.
This tool runs in your browser and needs JavaScript.
The name must also match the folder that contains the SKILL.md.
Paste a SKILL.md to check it.
How to use it
Paste your SKILL.md
Copy the whole file, header included, into the input.
Read the result
Errors stop the agent from loading the skill; warnings flag an Anthropic-specific rule or a file that is too long.
Fix and try again
The check runs again on every change to the text.
Frequently asked questions
Is my file sent anywhere?
No. The check runs in your browser; the pasted text never leaves your computer.
Which rules are checked?
Those of the open Agent Skills standard (header, name, description, compatibility, length), plus two Anthropic-specific rules, shown as warnings.
Does the checker test what the skill does?
No: it checks the shape of the file. To know whether the skill does its job, install it and try it on a real task.