what are employers allowed or not allowed to put on annual employee evaluations?

Answer 1

Allowed:
Anything related to your performance
Anything related to the job description
Usually, there are categories such as technical ability, knowledge of the duties, knowledge of procedures, working well with others, completing tasks on schedule and on budget, etc.
Also, things like poor attendance can be included

NOT allowed:
Anything not directly related to the job such as sexual orientation, religous beliefs, family situation, political beliefs, etc.

There are local (or state) laws that could vary from location to location that may slightly modify the general concepts outlined above.

Answer 2

Employers are pretty much allowed to put everything on an annual evaluation. Generally though it is about your performanc,attendance,attitude,and how well you get along with your fellow coworkers. There should not be any "gossip" on it.