What it is
Published as an open standard by Anthropic, whose business is the Claude models and products. The format’s own showcase lists Claude, ChatGPT, GitHub Copilot, Cursor, Gemini and around thirty other assistant products as supporting it.
A skill, the format’s name for one written method, is a folder with one required file that carries a short name and description plus the instructions in plain text. The folder can also hold reference documents the assistant reads when it needs them, templates and lookup data, and scripts it can run. The description is what the assistant reads first to decide whether the skill applies to the task in front of it; the full instructions load only then.
The format is free under an open license and needs no account, fee or vendor relationship. A skill written for one assistant works in any product that supports the format, which is what lets an expert’s method outlive any single tool.
What marketing teams should take from it
- The unit is a folder, not a prompt. Instructions, the proof the assistant may cite and the examples it should imitate travel together, so the method does not live in one person’s chat history.
- The description decides when the skill is used, so it should say both what the job is and when to apply it, in the words a colleague would use.
- The specification recommends keeping instructions short and moving longer material into reference files, which suits marketing methods that lean on approved claims and worked examples.
- A skill can carry a license of its own, so a company method can be marked private while the format stays open.
- It ships no content and no guarantee. Whether the assistant follows the method well is still tested on real requests.
Where to start
Start with the asset your product marketer corrects most often, as finding 01.1 sets out. Sit with them for an hour and turn their checks into a skill: the questions they ask before accepting a claim, the proof they accept, one approved example and one rejected example with the reason. Put the approved claims list in the reference folder.
Use it on the next ten requests and count how many pass first review. Give the folder a named owner in product marketing and keep it where marketing ops can track changes to it, so the next release updates the method rather than the inbox.
Keep in mind
Only as good as what is written into it, and not every product supports every part of the format yet.