This is about 8 years ago and the guy said he'd only been added by Boras a few years earlier. He largely handled endorsements and Boras still Boras negotiated almost every player contract himself. But they had a support staff of over 50 that worked with players and produced these binders of information for every free agent that was distributed to interested teams. It was fascinating to hear the inner workings.
I strongly considered going into agent work, but it's a field that isn't going to grow much and requires new entrants to make next to nothing for many years on the off chance they make it big in the long run. Also, many agents end up babysitting players more than anything else. Unfortunately, with a family it just wasn't realistic.