How do I stop using ssh-agent?

I use my keys without any password because all machines involved operate in a fairly closed environment. So I do not need ssh-agent. But I accidentally ran a script that seems to have enabled it use, and I cannot get it to stop. I can kill the process, but upon next boot, since the 'decrypted' key isn't in the cache, I am not able to ssh without the error message: sign_and_send_pubkey: signing failed: agent refused operation The 'culprit' seems to be $SSH_AUTH_SOCK. Will all of this be solved if I just remove that? Or is there a better way? **EDIT**: The $SSH_AUTH_SOCK variable only exists when I check from a terminal in my GNOME desktop. If I check from a tty, it returns nothing.