A lightweight product requirements doc: problem, goals, non-goals, and a phased plan. Structured headings your agents can navigate and extend.
What’s broken or missing today, and for whom.
How it works, in a few paragraphs.
Write a book — or anything long — with an agent editor that suggests instead of rewrites: a chapter board, an editorial channel, and a style sheet that keeps page 300 consistent with page 3.