It's excellent of the French to provide assistants (5)
I believe the answer is:
aides
'assistants' is the definition.
(aide is a kind of assistant)
'it's excellent of the french' is the wordplay.
'it's excellent' becomes 'ai'.
'of the french' becomes 'des'.
'ai'+'des'='AIDES'
'to provide' acts as a link.
(Other definitions for aides that I've seen before include "Right-hand men" , "Ministerial assistants" , "They help" , "Military assistants to a senior officers" , "Adjutants" .)