A cover has one job: tell the right reader, in a second, what kind of book this is. A clear brief helps a designer do that. A vague one produces guesses.
Start with genre and reader
Covers in a genre share signals: typography, colour, imagery. Readers use them to decide whether a book is for them. Look at books you consider comparable and note what they have in common. Your cover should feel like it belongs on that shelf.
What to include in the brief
Keep it to one page:
- Title, subtitle, author name exactly as they should appear.
- Genre and a two-sentence summary of the book.
- Three to five comparable books whose covers you like, and why.
- Format: ebook, paperback or both, plus the page count if known.
- Anything you want to avoid.
Giving useful feedback
Describe the problem, not the fix. "The title is hard to read at thumbnail size" helps more than "make it bigger", because the designer may have a better solution. Check every draft at small size, since most readers first see a cover as a thumbnail.