I've been suffering from a bad case of agent spam in my Caesar in Gaul campaign so I put together this little mod which reduces the AI's agent budget to zero.
This means that the AI can still have agents but it can't spend any money on preforming actions. Therefore all they can do is deploy their agents.
I may create another version with a small but non-zero budget if people want it.
Get it here:
http://speedy.sh/X9kST/reduced-ai-agent-budget.pack
Or on steam:
http://steamcommunity.com/sharedfile.../?id=210070083