Or poison the farmhands.

Anyway, the AI actually seems to use its agents intelligently, which is really nice. And while I'm finding a use for rakes and gentlemen in my latest campaign, I miss watching the pips on my assassins and spies rising slowly and surely to rank of 6* master spy or master assassin.
They should patch in a short "Infamy" scroll to the agents window, listing their kills, duels, sabotages etc.