Any buyer's representation agreement should have what the broker's obligations to you are. I can't imagine one without it. There is a standard Texas Association of Realtors Buyers Represenation Agreement and it does spell out what the broker's obligations are. Should be something like:
1. Use best efforts to help you find a suitable property in the market area.
2. Assist client in negotiations to aquire the property.
I agree with you that any contract you sign should be explained to your satisfaction and typically will obligate both parties to contribute to the outcome. Usually there is some give and take in most contracts. You do this and I'll do that. I'll do this for you and in return you'll pay me X.

If you'll send me an e-mail I can send you a copy of one of the standard contracts.