Is it correct and polite to end business letter with "Noted. Thank you" as an answer to a letter informing about task completion?
Brevity in writing can be mistaken as impolite because there is not enough material to determine tone, so the reader can find a tone (based on their expectations or personal biases) that is different from what the writer intended. Brevity in speech doesn’t have the same problem because the listener can hear the speaker’s tone directly rather than having to guess it from the words chosen.
Also, brevity of words can be interpreted as brevity of thought: if you didn’t put much effort into your response, then how much thought did you put into what you responded to?
Both of these factors can be canceled out if the person you’re replying to knows this is just your personality/style, but strangers don’t have that benefit.