I don't what's standard for the publishing industry, but I basically wrote the jacket copy for my first two novels (with a few minor tweaks by my editor that I didn't even know about until the book was published). For The Suicide Collectors, St. Martin's initially sent me this as the jacket copy:
In a few years time, The Despair will hit the Earth. It's not kind to its victims. It's victims aren't kind to themselves. Most of the population is dead, and the few that aren't, are struggling to stay alive. This is what Norman goes through day in and day out, in the ravaged state of Florida. But when his wife succumbs to The Despair, all of that is about to change. The Suicide Collectors, a group of bandits that steal bodies, arrive to claim his wife's body for their own. Norman won't allow it. He draws a weapon on them and shoots in cold blood. No one has ever done this before. All he wants to do is give his wife a proper burial. But now, everything is different. He can't stay at home.He has to do something. It's rumored that in Seattle there exists a scientist who can cure The Despair. But in this dystopian future, it won't be easy to get there.
Here's what it looked like after I hastily rewrote it:
The Despair has plagued the earth for five years. Most of the world’s population has inexplicably died by its own hand, and the few survivors struggle to remain alive. A mysterious, shadowy group called the Collectors has emerged, inevitably appearing to remove the bodies of the dead. But in the crumbling state of Florida, a man named Norman takes an unprecedented stand against the Collectors, propelling him on a journey across North America. It’s rumored a scientist in Seattle is working on a cure for the Despair, but in a world ruled by death, it won’t be easy to get there.
Writing copy for your novel is one of those things that really isn't covered by graduate writing programs (at least it wasn't covered by mine) but is absolutely crucial in the marketing of your novel. Like a query letter, each word in your novel's summary is very, very important and needs to represent your novel as clearly, concisely, and awesomely as possible. This summary will be affixed to the back of your novel forevermore and will represent it on every sales website, library catalog, and bookshelf in the world. It's also a good test for a novel as you work on second and later drafts: if you can't write a good paragraph summary of your novel by then, chances are you need to make a few more choices and hammer out a clearer structure for it. Today's readers (such as myself) have little patience as they shop and like shiny words that help them suss out what a novel's about in ten seconds or less. If you can't bring the clarity (and also make it sound really damn appealing as well) then it's back to the lab again.