As everything else in life it's a matter of balance and how you get your message across. You don't want to be the ass who never helps people if it's not his dir

As everything else in life it's a matter of balance and how you get your message across. You don't want to be the ass who never helps people if it's not his direct task. But then you also don't want to a pushover who lets himself constantly being distracted. I have done both. I think most important is to be clear and compassionate when you say "No".