Say assessment will include review of written work (5)
I believe the answer is:
essay
'written work' is the definition.
'essay' can be an answer for 'work' (thesaurus). I'm not sure about the 'written' bit.
'say assessment will include review' is the wordplay.
'include' says the answer is hidden in the clue.
'review' says the letters should be written in reverse.
'yasse' is hidden within 'say assessment will'.
'yasse' reversed gives 'ESSAY'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for essay that I've seen before include "example of Hazlitt's work" , "Short treatise" , "School composition" , "Trial, piece of writing" , "Prose composition" .)