damirp is absolutely dead on.
I do not currently have an agent. However, after two "insider" recommendations on my behalf, I got phone calls from both Gorfaine and First Artists, interested in having "exploratory meetings." That's code for, "tell us why we want to take 10% of the money you're already making without us," and that's exactly what those meetings entailed. They begin with a lot of knob slobbering, of course, about how brilliant you are, etc., and how bright your future is, but very quickly they just want to know that you're already signed to an A-list film with an A-list director. It's just about the money. They don't get you work. They just take your money. But for their 10%, they'll negotiate your contracts for you (which a lot of people have handled by a lawyer separately anyway, like I do) but also, at the highest levels, they're just sort of "part of the process." Like, you just have to have them there. Deals have to be handled by your agent or your lawyer, and your agent is likely the one with the access, having the lunches, doing the "thing" around town. So in the end, in my case, my meetings did not lead to representation. I had no A-films to bring them. And one of them told me point blank they didn't have the clout to just pick up the phone and tell some director or producer, "trust me, I've got the guy and you should hire him." That is the stuff of yesteryear fantasies. And if THEY don't have the clout, nobody does. They can parlay previous successes into more successes at the same level, but probably so can you. Moving up? That's back on you again.
And this is true at every agency. Just the "how much money are you going to give us," number scales with the size and clout of the agency. Smaller agencies will accept composers who bring in smaller commissions. But no matter what, you have to have made the connections, gotten the deals, built the relationships, and deliver the product all on your own. This is one of the reasons that having absolutely solid "in the room" social skills is a must. Talent has nothing to do with getting work. Our industry is just overflowing with marginal or talentless composers working on films - big films - all the time. Including a few "up and comers" I can think of who could be outwritten by most of us if you woke us out of a drunken stupor in the middle of the night and gave us 30 minutes and a pencil. Talent is simply why they'll remember you or not, when it's all over. So keep your focus on meeting and courting those directors and producers. They're who you'll work with anyway.
_Mike