The pact I unexpectedly found to be miserably inadequate (8)
I believe the answer is:
pathetic
'to be miserably inadequate' is the definition.
(I've seen this in another clue)
'the pact i unexpectedly' is the wordplay.
'unexpectedly' is an anagram indicator.
'the'+'pact'+'i'='thepacti'
'thepacti' with letters rearranged gives 'PATHETIC'.
'found' acts as a link.
(Other definitions for pathetic that I've seen before include "Hapless, miserable" , "Derisory" , "Touching and pitiful" , "Contemptible" , "Tip cheat - truly sad" .)