1. He's a great guy. He's fun to talk to, fun to email, fun to have lunch with.
2. He gives good notes. He's smart. He's hard-working.
3. He has one characteristic that is so unusual in an agent that I can't even tell you, and that is this: he knows his own opinions. If he likes a script, and sends it out, and it is rejected, he does not stop liking the script. If someone else has a criticism of the script, he will consider it, but he will not suddenly toss the script aside as hopelessly tainted because someone else didn't like it. He has a strong and integrated personality. He knows himself and understands that other people are different. People like that are very rare. Find them.