Don't Spare the Pleasantries
There is a time and a place to be direct. A pet peeve of mine are those who are direct out of habit rather than necessity. I'm a big fan of when you either spear or write to people, especially those you don't know, never ever spare the pleasantries. It is just being polite. Thinking back to my early creative writing classes, I recall statements like "trying to know your audience" or "maintaining proper tone". Being direct sets a tone that can be read as being aggressive, bossy, or in some cases rude.
When a manager writes to their direct reports there may be times where being direct is the right way to go. This works well to give a specific direction or denoting a sense of urgency and even frustration. As a general rule good managers know it sets a poor example as "this is the way a manager behaves to their subordinates". Coworkers need to take an almost identical approach to their colleagues. The only exception to their interaction is they are equals within a department or coworkers across departments. Everyone is working towards the same goal and while you'll get the point across, a few other things not quite as positive go along with it I've already touched on.
Not to sound cliche but treat others as you wish to be treated. It is no different when speaking or writing.