The act of describing helps you to have a range of vocabulary besides the basic. It is important to know how to describe a person in English because if you are in a situation in which it is necessary to do it you are going to be prepared; and if you have the need to express how a person is it going to be easier if you know the correct vocabulary.
In this webquest you are going to learn the vocabulary for describing people, what are the appropiate words and what are not in order to do a good description.