I am a relative beginner and would appreciate advice on determining whether or not a stamp would be suitable to use for trading. I do not intend to post any stamps for trading on this site at present. I only wish to gain a better understanding of how to make a proper determination of a stamp's condition to know whether a stamp that I am not interested in should be saved for a possible future trade or thrown away.
Here is a sample stamp.

This stamp has a few perforations torn off in the upper left corner. Would it be acceptable for use in trading or should I just throw it away?

I realize this question is somewhat subjective, but any advice would be appreciated.
Thanks