I wonder if this would be possible, but I have a feeling it is not.
Phishing seems to be rampant these days, and, I wonder if secret agent could not be made to check for the typical tell-tale signs of it, when you go to some website and use secret agent to enter credentials.
Maybe it could be made to check whether the visible url is different from whatever url the phishing site is using in the background?
Since it is not a browser plugin, this might not be possible. But it would sure be cool if it could.