A logo should be Appropriate to look or feel right to be there to represent what you do. For example, if it’s in sports, it should be Bold and Dynamic or if it’s in fashion, it should be elegant.
It should be unusual enough to be Distinctive and Memorable in our minds. It’s a good logo if you can look at it once or twice, then make a rough identifiable sketch.
Finally, it should be Simple enough to be reproduced in different sizes, different formats and be identifiable no matter how it’s being used.