Fuss over tip - it has to be finished (2-2,4)
I believe the answer is:
to-do list
'it has to be finished' is the definition.
The definition suggests a singular noun which matches the answer.
'fuss over tip' is the wordplay.
'fuss' becomes 'todo' (both can mean a commotion).
'over' means one lot of letters go next to another (in a down clue, some letters go over others).
'tip' becomes 'list' (both can mean to tilt).
'todo'+'list'='TO-DO LIST'
Can you help me to learn more?
(Another definition for to-do list that I've seen is " Activity inventory".)