Yeah, keeping it short can be pretty difficult sometimes. It's a useful skill to have. For example when you need to tell someone something without wasting much time, like when you are in a hurry.
One time I wrote a long email to someone. And they only skimmed it and then asked questions that were directly answered in the email.
Ever since, I've been keeping my messages short so no one can claim that their pet piece of information was not included in my email. For example, that one time someone asked a really stupid question, and I thought the shortest possible way to answer would be to call the guy a moron. It was very effective. I have no doubt that the guy understood every word in my email. Despite being a moron.
Calling people morons isn't very good either, however. I once called a guy a moron, and he wasn't too happy about it. I could see it in his facial expression. It's good to be able to read facial expressions. He also came running after me, which I would have understood even if I hadn't read his expression though.
So to summarize: under many circumstances it might be better to keep it short rather than long, because people might misunderstand you otherwise, but there is a fine line between a good concise statement and insulting people.
Thank you for your attention. Please also read my previous comment about the meaning of life.