There is a sentence in my study guide that says " many of us unconsciously fall back on a whole list of words that say precious little."
this doesn't make sense to me i'm on a study guide for word structure and see something like that this an incomplete thought?

No, it's just supposed to make you think. It just means that people should actually think of what they're saying and choose descriptive words. A lot of the time, people use words that have rather simple or ambiguous meanings. For example, if someone says they feel good, that really doesn't tell anyone much of anything. What does it mean to feel good? It could mean you're really happy, or just mean not feeling bad. Instead, you should say exactly how good you feel, and why.