Poet's always including the writer's title (5)
I believe the answer is:
emeer
'title' is the definition.
(I have seen 'Islamic title ' mean 'emeer' so perhaps 'title' could also mean 'emeer')
'poet's always including the writer's' is the wordplay.
'poet's always' becomes 'e'er' ('e'er' is a poetic term for 'ever' or 'always').
'including' is an insertion indicator.
'the writer' becomes 'me' (the person who wrote the clues).
'eer' going around 'me' is 'EMEER'.
(Other definitions for emeer that I've seen before include "Meryl -, US actress" , "Prince" , "independent ruler" , "Leader of Arabs" , "Islamic title" .)