There is none. I would love it for you to be as detailed as possible, but it's not a requirement. If you simple want to post the following:
"Colt McCoy doesn't have a big arm, but neither did Drew Brees, and plays in a similar offense and is a mobile guy. And I think like Brees he'll be a good to great starter in the NFL."
That is perfectly acceptable.
Personally, I'm going to use the same format I did last year, which is each prospect is broken down in the following categories:
Pros: What he does well
Cons: What he doesn't do well.
Overview: A basic summary of the player, and also contains notes about his career in college such as injuries, stats, or the scheme he played in.
NFL Forecast: A projection of what I expect the players' NFL career to be like.
ATL Forecast: A projection of what I expect that players career to be like if he was on the Falcons.
Value: My opinion on where this person should be drafted.
And for some of the better prospects, I might break down how they stack up in different skills/categories, such as Arm Strength, Accuracy, Decision Making, etc. for QBs or Speed, Ball Skills, Man Coverage abilities, etc. for CBs.
But others are free to break down prospects in whatever format they are most comfortable with. If it takes them 500 words or 5 words to do it, then so be it.
"Vincere scis, Hannibal, victoria uti nescis" -- Maharbal, 216 B.C.E.