It's like they're trying to prevent you from going straight to the company, to where they won't get their finder's fee, but all it does is ensure they only get responses from people who are desperate.
I understand them wanting to protect their sources, but they have to give some details. "I have a Java backend position in the telecommunication sector, it would be on the client's (whatever team) that (does whatever). I'm looking for a developer with 3-5 years experience in Java or other static OO languages; the client uses (frameworks), and some knowledge of (tech, tech, and tech) would be helpful as well. Compensation is competitive, the pay is a bit better than average, standard benefits" would be the elevator pitch that might actually be worth paying attention to (well, no, because I don't want to go back to writing Java, but you get the idea).
In short, I want to know -something- about the job beyond "it's a bog standard development job". I can find a bajillion of those posted online, without having to call and actually -talk- to someone. Show me that you actually know what the position is about, and might be able to answer questions about it before I actually talk to the client, and I might respond.