The other day on Twitter at #CorvisieroQueries I posted about motivation and continuity. I believe that both are equally important, tools that will help hook your audience, so that they want to keep reading. Too often I'll come across a query with some really nice description, but unfortunately tells us little about the character or motivation. In my humble opinion, motivation is second only to plot. Motivation helps drive the story forward. Why is your character behaving a certain way? What does your character want? How are they going to get it?
Along with motivation, continuity helps ground the reader in the world you're creating. If you jump around too much, it's so easy to get lost. Make sure your reader is right with the characters in the story. I'd also like to mention be consistent with voice. I've come across a number of submissions that begin in 1st person and then will switch to 3rd, or will begin in past tense and go to present. Always be consistent!!