Told what to do in specific terms (8)
I believe the answer is:
detailed
'told what to do' is the definition.
I can't tell whether this defines the answer.
'specific terms' is the wordplay.
'specific' becomes 'detail' (synonyms).
'terms' becomes 'ed' (I am not sure about this - if you are sure you should believe this answer much more).
'detail'+'ed'='DETAILED'
'in' is the link.
Can you help me to learn more?
(Other definitions for detailed that I've seen before include "Giving full particulars" , "Showing even small features" , "Showing attention to fine features" , "Itemized or intricate" , "Particular" .)