'Tools for the job' is an English retort meant to be heartless (9)
I believe the answer is:
equipment
'tools' is the definition.
(I've seen this before)
'retort meant to be heartless' is the wordplay.
'retort' becomes 'equip' (I can't justify this - if you can you should believe this answer much more).
'to be heartless' says to hollow out the word (remove centre letters).
'meant' with its centre removed is 'ment'.
'equip'+'ment'='EQUIPMENT'
'for the job is an english' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for equipment that I've seen before include "Kit, apparatus" , "Apparatus, tools" , "Items needed for a particular purpose" , "4 [TACKLE]" , "Stuff" .)