Start with a plain document.
Write in your own words. Keep the first version short enough to read in a few minutes. Use information you’re comfortable placing in your chosen AI tool and remove private customer details from any examples.
What do we do?
Describe the business, the people you help and the work you’re responsible for.
How do we work?
Capture the few things that explain your standards and the way you communicate.
Where does the knowledge live?
List the tools and documents the team uses. Describe what each is for. Don’t include passwords or access keys.
What would be useful first?
Pick one repeated task. Explain what starts it, what a good result looks like and who checks the work.
What stays with a person?
Write down the decisions that need someone’s judgement and the things an assistant should ask about instead of guessing.
Try it on one small job.
Use the document as context in your chosen AI assistant. Ask for a draft for a familiar task, then compare the result with what you’d actually use. Add the missing context and try again.
That’s the beginning of a business brain: useful knowledge that improves as you work with it.