I'd say very good. The value of a spy is in the information distributed not not getting caught. The other problem is the vast majority of the performance data we have is from agents, who were caught, so it's difficult to compare and contrast agents who were caught vs. those that aren't. We also don't yet know what information they passed.

"possibly the worst intelligence disaster in US history." http://en.wikipedia.org/wiki/Robert_Hanssen

shimon wrote "agent" meaning "real estate agent", as the article did.

ehnus' comment is a pun that uses "agent" as in "spy". </joke_explainer>