Taking up little space in the agreement (7)
I believe the answer is:
compact
'taking up little' is the definition.
'compact' can be an answer for 'little' (I've seen this before). I'm not sure about the 'taking up' bit.
'space in the agreement' is the wordplay.
'space in' becomes 'com' (I can't justify this - if you can you should believe this answer much more).
'the agreement' becomes 'pact' (pact is a kind of agreement).
'com'+'pact'='COMPACT'
Can you help me to learn more?
(Other definitions for compact that I've seen before include "Agreement - brief" , "Concise" , "bargain" , "Small case for face-powder" , "An official agreement" .)