Should I Worry If My Performance Evaluation Is Outstanding In All Aspects Without Any Suggestions For Improvement?
If you receive only information about what you do well during your performance evaluation, and no information about how you can get even better, it isn't a good use of the time. But to answer your question, it's not really a problem if you are told that you are doing well -- just keep doing what you've been doing.
Some managers aren't comfortable with the performance evaluation process, and so tend to shy away from giving advice on how to improve performance. So, that's one reason why they might not offer suggestions.
So, heres, the tip. Ask your manager or supervisor if he or she has any suggestions about how you can get even better. He or she may not be able to give any, but simply asking protrays you in a positive light as someone who wants to be involved in continuous improvement.