Simple clue I can’t do MP compiled (13)
I believe the answer is:
uncomplicated
'simple' is the definition.
(I know that simple can be written as uncomplicated)
'clue i can't do mp compiled' is the wordplay.
'compiled' is an anagram indicator.
'clue'+'i'+'cant'+'do'+'mp'='clueicantdomp'
'clueicantdomp' is an anagram of 'UNCOMPLICATED'.
(Other definitions for uncomplicated that I've seen before include "Simple" , "Straightforward" .)