Generally what we are looking for in the biography section of the application is some indication of the proposed character's persona and background. Who are they? Where do they come from? What motivates them? Then, in the hypothetical scenario, we want to see that persona, that background, that motivation, that character applied to the facts that are posed.
Accordingly a biography that gives us only the race, alignment and class of the proposed character is not going to pass. Neither is a biography that only discusses the character's history - while we do wish to know something of the character's history, we need to know a little about the character's persona as well. History is not enough, but it helps illustrate and illuminate personality.
A good personality description is required, but it is not enough by itself - we want to see that personality applied in the hypothetical scenario. For example, someone might write a biography for a chaotic good elf whose parents were slain by drow and whose major motivation is revenge against the dark elves, but if that applicant answers the hypothetical scenario (which involves a mysterious drow stabbing a nobleman who is leading a slave-child on a chain) by stating that he would bargain with the dark elf in the scenario to split the cost of selling the child at a slave auction, well, then we would question whether or not the person can actually role-play.
So - this is a role-playing project. What we are looking for is some evidence that an applicant can develop a three dimensional persona for their character - something beyond "I am a NG dwarf cleric of Moradin who hates drow" - and we want to see some evidence that the applicant can apply that persona in-game.
