Sure, but one of the 'hints' as to the type of prospect he is would, in fact, be that he was drafted by the Patriots in the 3rd round. It tells us that every team in the league viewed him as not being worth taken in the first two rounds, either because of his talent or because they felt he'd fall lower. It also tells us that the Patriots, one of the league's better drafting teams, felt that a 3rd round pick was worth using on O'Connell, despite the team already having Brady.
The significance of that being a 3rd rounder is that it makes it difficult for the quarterback chosen to be looked at strictly as a later trade investment, because it would be tough to convince other teams to give up a lot more than a 3rd for a player who won't be seeing the field, and just pushing the 3rd pick into the next season for a pick one round higher is a tactic the team uses all the time but chose not to do in this case. That means that the team either couldn't find a taker for the trade, or they valued the kid as high as a second round pick in the next season's draft. Developmental guys being prepared for trades are usually taken lower (Brunell in the 5th, Hasselbeck in the 6th, for example), so that there's a worthwhile return on investment. Getting a 2nd rounder for O'Connell after putting in 3-4 years of development won't be any kind of enormous coup.
So, drafting the kid in the 3rd round tells us that Belioli had picks to waste (doubtful), Belioli just wanted the kid as a potential develop/trade kid (possible, I'd guess under 50%, though), or, what would appear to be most likely to me, Belioli thought they could coach this very raw prospect up into a legitimate NFL quarterback to serve behind Brady and/or replace him given the need.
Despite Maverick's responses, that does tell us a fair bit. Sometimes the best place to start is the most obvious.