Some book covers try to tell you every thing you’d ever want to know about what’s inside the book. You’ll see star bursts, triangles on the corners, boxed text, copy above the title, copy below the author’s name, there’s so much going on you don’t know what to look at let alone comprehend first. Then you turn the book over to the back-cover and it’s not much better.
I suggest taking a second look at exactly what all that information is going to do. Ask if it is really necessary;
1. will it add to the interest level of the content;
2. will it make the reader look at the back cover;
3. is it ‘yelling’ at the reader. Then edit and “make it work” with less.
The more time and effort you put into the over all comprehension of your book and it’s parts the better received it will be.