Acid test for what you should do

There was a classical acid test for judging if a certain thing is moral or not. That is the "Newspaper Test": if you do this particular thing, would you want to see it reported on tomorrow's newspaper headline?
If not, it's not moral.

I just found that there is counter-part of this acid test for "work priorities". That is: if your boss want you in his office in an hour, what you should do in that hour.
If the thing you are working on is on that list. It's high-priority, otherwise, it's not.