Annoying book covers — shoots the top off (8)
I believe the answer is:
tiresome
'annoying' is the definition.
(I've seen this before)
'book covers shoots the top off' is the wordplay.
'book' becomes 'tome' (a tome is a book).
'covers' is an insertion indicator.
'shoots the top off' becomes 'ires' (I can't justify this - if you can you should give a lot more credence to this answer).
'tome' enclosing 'ires' is 'TIRESOME'.
Can you help me to learn more?
(Other definitions for tiresome that I've seen before include "So metier may be boring (8)" , "wearing" , "Like a pain" , "'Tedious, irksome (8)'" , "Boring, irksome (colloq.)" .)