Being brief in your writing is very important in this world of ours and its "catch me quickly" attitude. I mean, come on. Twitter anyone? 140 characters and that's all folks.
So, how do you know when you are NOT being brief? Well, by using words that are not necessary. Sometimes I think we repeat ourselves and don't even realize it. Like saying, the blood pooled around the body and in the next sentence or two talk about how the blood around the body had made the carpet wet or how it looked like a blood bathtub, outlining the corpse. Isn't that basically the same thing? Couldn't you say it all in one sentence?