What's in the brief
The search intent (what the searcher wants), a title tag and H1, a suggested length, five to eight H2 sections with the points each should cover, questions to answer, and related terms to use naturally. Copy it as Markdown and hand it to a writer, or use it to check an existing page for gaps.
Use it with real data
AI suggests a structure, but the best pages also answer what your own visitors search for. Compare the outline with the search terms in Google Search Console, or upload your export to the Search Console analyzer.