Fine list of items missing the last bit — the bit that doesn't matter (3,3)
I believe the answer is:
'the bit that doesn't matter' is the definition.
(fag end can mean the least important part)
'fine list of items missing the last bit' is the wordplay.
'fine' becomes 'f' (abbreviation).
'list of items' becomes 'agenda' (items for discussion at a meeting).
'missing the last bit' means to remove the last letter.
'agenda' with its last letter taken away is 'agend'.
(Other definitions for fag end that I've seen before include "Useless bit" , "'Cigarette butt at last (3,3)'" , "Cigarette butt, the last part" , "Last and worst part" , "worthless piece" .)