"read the book to find out" is a bad description

thy must actually write something for your novel's description. vague one liners are okay for one shots, but for real books, yOU NEED TO DESCRIBE IT

your description is the thing that lures people to your book, before your first chapter even comes into play. you wont get people to read your first chapter if your description sucks.

the key to a perfect description is to give just enough information for there to be a mystery-

Grim had messed up big time.
As the son of the god of death himself, he had been able to get away with a lot of things. His brother/bond creature Artemis always pulled him out of hot water everytime he screwed something up (which happened pretty often). Grim felt his reputation was as immortal as his body.

But not now. It turns out unleashing an evil chaos goddess onto the moral world was the final straw.

Alone and hated, Grim must find a way to finally reverse all of his mistakes.

(-Highway to Hell)

So, yeah, the art of description writing is a little harder than writing the actual novel. It really helps if you have everything planned out.

In general, it should cover the first couple chapters up to the plot trigger (which in hth's case was the unleashing of a chaos goddess) in detail and then the rest should foreshadowing/establishing conflict. It is NOT a summary. It's a little taste to get the audience interested and wanting to find out more.

But, do NOT write a whole big in the description box. Leave some things to the audience's imagination. Find that happy medium of information vs mystery.

Descriptions are hard.