Answer:
It's all based on blurbs. Technically speaking, you should have everything from a 10 or 12 word log line to a 250 word blurb created before you start selling your book. A 30 second sales pitch is a blurb. If you get past that, you should have market information and so forth ready to continue with.
Don't waste time stating the genre and tone of the book. Your blurb should make that clear. Ideally, the blurb should match the book in tone. You can check my web site for more information on writing blurbs.