You've mentioned two beliefs:

- the person is using a rude tone

- they are doing it for reason X

Neither of these are objective facts.

If I had to deal with a situation like this, the first thing I would do would be to examine what I have actually observed.

You may have a theory (e.g. "he uses few words and doesn't start with pleasantries before making a request" -> "he is intending to be rude"). But making that theory explicit will better allow you to examine it.