Agent who changes players going round country with no capital (8)
I believe the answer is:
catalyst
'agent who changes' is the definition.
'catalyst' can be an answer for 'agent' (I have seen 'Agent of change' mean 'catalyst' so perhaps 'agent' could also mean 'catalyst'). I am unsure of the rest of the definition.
'players going round country with no capital' is the wordplay.
'players' becomes 'cast' (I've seen this before).
'going round' indicates putting letters inside.
'country' becomes 'italy' (Italy is an example).
'with no capital' means to remove the first letter.
'italy' with its first letter taken off is 'taly'.
'cast' enclosing 'taly' is 'CATALYST'.
Can you help me to learn more?
(Other definitions for catalyst that I've seen before include "Substance improving a chemical reaction" , "Long journey (by sea)" , "Agent promoting change" , "Chem. reaction enhancer" , "Person or thing that precipitates change" .)