I think the "medium" (twitter/mail/messenger) and its "limitation" do not matter a lot. I think it mostly depends on the sender and the receiver (and its circumstances). If they have a mutual understanding (same "degree") of the message, the communication MIGHT be more efficient due to lessen time delay. Nevertheless, the sender might use the wrong words ... speaking Portuguese ... you see where this leads ... also, and most fascinating ist the "time factor". Like: "Do you need time to understand / grasp something?"
So as I see it: The communication medium itself is almost always not responsible to for "better human communication". BUT, as all rules, there are exceptions, for example, twitter is a medium that can, with one "tweet", move a whole flock of birds at once (I think this was the initial intention of twitter ... philosopical seen). This "reach" (unprecedented before) opens up a whole new slew to "human communication". Like with one tweet:
1: Some Trump might declare war with ($random-country)
2: A Country might revolt (see Arab Spring)
3: Stock Market might break ...
By the way, not sure if you might like it, but "Cognitive Load" is a very interesting topic in itself. Its about your own possibility to grasp/understand/dissect things. Its mainly about "basic" things that, when cumulated, are totally obvious OR totally confusing. In my opinion, this is the main key to "better human communication".
But to end this topic, here is my recent -Word of the Week-:
If you can't explain something well, its likely you don't understood it either