what is the right word

You can read some comments on the back cover of some books on their contents by some well-known people whose words are thought to be law in the field the book is related to.

"This is a heart-breaking story about..."

My definition is a bit convoluted -- could you edit it, please?

Second question: what is these comments called?

I know they have a name, and it is on the tip of my tongue -- I have been stuttering here without avail for half an hour -- please, help me.

thanks