The agent’s answer
The final block of sections takes up roughly half the proposal by page count, but Kelly does not give it the same weight as the overview or marketing. The book's own table of contents should be written so plainly that it could be copy-and-pasted straight into the manuscript, listing introduction, numbered chapters with titles, a conclusion, and any back matter. Chapter summaries are the deep dive that follows, where the writer justifies, with confidence, why the material is ordered the way it is, treating the editor as a captive audience who needs the full order laid out rather than a reader to surprise. For the sample chapter, she recommends choosing whichever material best demonstrates long-form writing ability, and if the book has more than one register, such as a practical, applied section alongside a more narrative, social-commentary section, sampling from both to display range, aiming for about 10,000 words total.