The answer to this question is a resounding no 99% of the time. While many brands include these little metal teeth, they usually diminish the overall functionality of a knife.
Serrations break up the edge of a blade, reducing your capacity for long, clean slices. That’s not to say they’re useless, however. If you find yourself dealing with a lot of rope or cordage, serrations are actually quite beneficial. But when breaking down cardboard, opening packages, slicing food, or carving, they’re definitely more of a nuisance.