the description of your book that goes on the book jacket, on sales sites, and in catalogs
Who writes copy for my book?
Your editor and/or an assistant. But this is your book, and you’re a writer, so consider asking to collaborate. You really want your copy to be clear and enticing so that your book will sell. If you see a description of your book go up on Amazon or Goodreads or anywhere else, check it right away to see if it’s what you want. If it’s not, consider asking your editor if you can make some changes.