Yes. The one valuable ability that is exclusive to a recruiter (and any other deal broker, like real estate) is to abuse their position as a trusted mediator to slyly violate confidentiality agreements to help the deal close: tell the company what salary what employee will accept and any competing offers, tell the employee about what the interviewer wants to hear, etc.

That is a double-edged sword, though, so be careful with it.

The recruiter (or any mediator) is a valuable tool to help the weaker side of a negotiation close a deal. Know which side you are.