Jason Yarn was previously with Paradigm Talent Agency (AW Thread | Website). He has now apparently left to start his own agency; however, I don't find a website. His Twitter account says that you can query him at a gmail account. He's not listed on Preditors and Editors that I could find, and googling brings up what I just linked plus his time at Paradigm.
It seems a little fishy to me. On the one hand, Paradigm is a huge media agency, which seems like a good background. On the other hand, Jason has left to start his own agency with no web presence and no indication of what genres he's looking for except for one vague tweet about it.