So enthusiastic, corruptly agree best contract (5,2,6)

I believe the answer is:

eager to please

'so enthusiastic' is the definition.

'corruptly agree best contract' is the wordplay.
'corruptly' indicates an anagram.
'best' becomes 'top' ('top' can be similar in meaning to 'best').
'contract' becomes 'lease' (lease is a kind of contract).
'agree' is an anagram of 'eager'.
'eager'+'top'+'lease'='EAGER TO PLEASE'

(Another definition for eager to please that I've seen is " Obliging".)

I've seen this clue in The Guardian.

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