> It's in your best interest to only use Developer-Approved Recruiters.
Brilliant idea, a Good Housekeeping Seal of recruiters.
Who exactly approves the Developers doing the approving?
Linkedin remains the best resource (social proof) to quickly ascertain if you're dealing with a legitimate recruiter or a complete bozo. Look for individuals with a long track record and solid industry background.
It's perfectly acceptable upfront to inquire specific details about their relationship with the client, history, contractual status, and process. If they can't answer those basic questions to your satisfaction, move on.
A good recruiter is interested in engineering a good match between his clients needs/priorities and the personal/professional goals of individual candidates. Not an easy job when dealing with humans.