What is a skills.md file?

Think of it as an SOP the AI reads

Any well-run business already has procedures: how a quote is put together, what a site report must contain, which checks happen before an invoice goes out. A skill is that procedure, written for an AI assistant instead of a person.

The ".md" part just means it is a plain text file with simple headings. You can open it, read it and change a line. There is nothing locked or proprietary about it.

What is inside one

• The purpose — one line on what this task produces and for whom.
• The inputs — the documents, notes or figures the task needs, and where they come from.
• The steps — in order, including the checks that happen along the way.
• The output — the exact structure, headings and level of detail required.
• The limits — what the task must never do, and what a person must approve.

Why it beats typing a request each time

Typed requests drift. One person asks for a summary, another asks for key points, and the results are not comparable. A skill removes that: everyone runs the same rules, so the second week's output can be put next to the first week's.

It also survives staff changes. When the person who worked out the good version of a task is on leave or moves on, the rules stay in the business rather than in their head.

When a skill is the right choice

• The task recurs, with the same shape each time.
• There is little or nothing to adjust between runs.
• One or two people run it, in the assistant they already use.
• The value is in consistency — same checks, same format, every time.

When to use something else

If numbers, dates or quantities change every run and somebody needs to set them, an artifact with a screen is easier to live with. If the output has to be presented to clients or several staff in one place, a site fits better.

Skills are also the foundation under the other three: an artifact or a site usually has a skill doing the actual work behind it.