The phrase "bites off too much" refers to someone attempting to take on a task or responsibility that is beyond their capabilities. Antonyms for this phrase may include "prudent", "measured", "cautious", and "temperate". These words convey an approach to undertaking tasks that is calculated, careful, and thoughtful. Instead of seeking out challenges that are beyond their abilities, a person who embodies these antonyms would only take on tasks that they are qualified for and have a reasonable chance of completing successfully. While it is important to push oneself and take on new challenges, it is equally important to know one's limitations and not bite off more than they can chew.