Nathan Bransford, literary agent extroardinaire, yesterday posted an actual query and the first page or so of a manuscript submitted to him (with the author's permission) and took the time to explain why he didn't like it.
A lot of commenters on his page (politely) pointed out flaws in the writing itself, and I agreed with most of them. However, I think the real problem is with the story idea itself.
Here's the main part of the query:
Katirin is a princess of such embarrassing parentage her family forced her into a convent to get her out of the royal succession. When she discovers the convent's bland and blissful priestesses--women who share a communal mind and do little except sing--aren't really the god's mouthpieces at all, but empty husks puppeteered by a demon, Katirin realizes she must find a way out of the convent or the demon will devour her soul.
For Katirin, however, escaping telepathic priestesses and irate nobility isn't enough--not when she can see the demon's hunger will one day destroy the nation she should have ruled. Katirin vows to stop the creature, but she needs to answer one question first--how do you kill a demon that lives in a thousand bodies?
Katirin sounds, well, vanilla. Generic. Like every other female protagonist in fantasy. She's good and noble and boring. This is a problem that I'm currently running into on my own manuscript, so I can relate. And for all I know, the author really develops Katirin into an interesting character later in the story, and just needs to work some of that flavor in here. But I maintain that some flavor is necessary. A query about a good, noble, selfless woman unexpectedly thrown into danger just isn't going to get the attention of an agent. What does she *want*, aside from not being eaten? Why should we care about her?
And that's the question it always comes back to, in all the advice I see out there. Make the agent care. Grab their interest. They get endless servings of vanilla in their slush piles- we've got to give them something different.
So I will be analyzing my WIP to make sure the main character's motivation is clear, and worthwhile, and something that people can really get behind. And to make sure that she's not boring. ;-)