Descriptions are always a good thing to have in your work. It can change a very boring sentence like “Bob yawned.” Into something that is positively fun to read like “Bob’s mouth opened so wide that he looked like an angry orangutan as he pulled in a yawn fit for a lion.”
The problem is finding the right balance. If you put to many descriptions in your writing then you end up with a very boring and hard-to-read piece of prose. This is mainly because of adverbs and adjectives. What? You ask, aren’t adverbs and adjectives how you describe things? No, not necessarily. You can do better descriptions in a more succinct and less boring way by using strong verbs and nouns. Instead of saying the boy ran to the store. You could say the teen raced to the mall. In one sentence and without any adverbs or adjectives I have given you a much better sense of what is going on. By saying teen I have specified the age of the boy, by using raced I am hinting that the boy is probably in a hurry, and by using mall I have showed how big the store is. Your chapter always reads much easier when you use more descriptive verbs and less adjectives.
SHOW DON’T TELL. When you want to describe a scene you don’t want to say something like Bob was horrified to discover that Jane had left him. That may use fine description, however it is much more interesting if you make the reader think a little bit. Bob hung up his cell-phone and slammed his palm against the wall...Sarah never understood! This shows the feelings without telling right out what happened which hooks the reader’s attention much better.