Tricky to do, anagram is for Luke's brick (4,9)
I believe the answer is:
good samaritan
'luke's brick' is the definition.
I can't judge whether this defines the answer.
'tricky to do anagram is' is the wordplay.
'tricky' is an anagram indicator.
'to'+'do'+'anagram'+'is'='todoanagramis'
'todoanagramis' anagrammed gives 'GOOD SAMARITAN'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for good samaritan that I've seen before include "Voluntarily helpful and sympathetic person" , "Charitable individual" , "Neighbourly type" , "Benevolent person" , "One giving disinterested help, maybe to a stranger" .)