It's perfect when I give people a hand (5)
I believe the answer is:
ideal
'it's perfect' is the definition.
(similar in meaning)
'i give people a hand' is the wordplay.
'give people a hand' becomes 'deal' (to deal a 'hand' in card games).
'i'+'deal'='IDEAL'
'when' acts as a link.
(Other definitions for ideal that I've seen before include "just the job" , "Most suitable" , "'Perfect, model (5)'" , "Ailed (anag)" , "Dream" .)