It should really clearly show readers why they should read through your book and allow them to determine what they might hope; it’s an ad for that book. It is far from your personal statement on why you wrote the book. (This generally goes on the inside book jacket flap https://kindledirectpublishing.health.blog/2024/09/28/creating-a-masterpiece-for-readers-through-the-art-of-book-formatting-and-layout/