You can look at this two ways: as a reader, and as a writer. Here’s my reasoning:
- As a reader I usually don’t need to know much about what your characters look like – I have an imagination of my own and my mind will fill in any details that you haven’t specified for particular purposes – but I do need to know what they SEEM like (to the POV character or narrator).
- As a writer I need to give you an evocative idea of their type and demeanor, but I can let you do the rest of the work yourself. I will only mention a specific body part or describe an article of clothing if that is the most efficient and poetic way of getting across the idea of this person. It is the IDEA OF THIS PERSON that I need to communicate, not the details of their taste in fashion, and I find that a short clause (like “work-scarred hands” or “haunted eyes”) can say a lot. This is not a movie, I am not a painter. If a few adjectives or a nice metaphor will do the job perfectly, there’s no need for any more words.