“If I had more time I would have written a shorter letter” - Mark Twain.
Brevity takes time because we have to trim our message down to only the essential facts. Brevity shows that you have a mastery of your subject matter. You've found the most simplified, yet accurate way of articulating your thoughts. If you know what you want to say...say it. If you don't know what you want to say, wait until you do. One of my favorite verses in the Bible reads,
When your words are few, each word is more valuable to your listener. Is there a time to be long-winded? Maybe if you're writing a dissertation. Otherwise, just say what you mean and mean what you say.