It's actually the opposite. Saying it like this is nicer, but it depends on the tone of your voice. A few other ways to say it is: Suck it up! (This is rude, or like commanding) Actually, anything that's with a question mark isn't really rude.

Polite: Do you need some/more time? Neutral: Are you ready? Rude: Hurry Up But everything can change based on the tone of voice as well.