He's right, I see, to be tough (7)
I believe the answer is:
richard
'he's' is the definition.
'right i see to be tough' is the wordplay.
'right' becomes 'r' (common abbreviation).
'see' becomes 'C' (the word for the letter, according to Chambers).
'to be tough' becomes 'hard' (similar in meaning).
'r'+'i'+'c'+'hard'='RICHARD'
(Other definitions for richard that I've seen before include "-- Strauss, composer" , "& 20 Down US President" , "-- Wagner, composer" , "man" , "Boy's name - Cliff?" .)