There are few things as frustrating as calls that go unreturned. From real estate agents. You know, people who make their living on the phone.
When you take the time to call an agent and make an appointment to show their property (and many agents in my area don't even bother taking those calls - they direct appointment calls to their sellers), and then take your clients to see that listing, it is common courtesy to the seller of that property to give the listing agent some feedback when requested. Maybe you and your buyer noticed a strong odor, or maybe the house was too cluttered and didn't show well. Maybe they decided to make an offer on another property. BUT YOU NEED TO TELL THE LISTING AGENT. They need to relay information to the seller, who took the time to get their home ready to be shown. So take those few minutes and be honest. Be nice, but honest.
And for you agents who don't answer or return calls when agents call to ask questions about your listings...do you have so much going on that you don't feel you need to talk to the agents trying to sell your property? You must be independently wealthy and are just "dabbling" in the business. How do your sellers feel about that?