You're not really explaining what you're trying to do, especially considering you're redirecting agent.tgz to something that has a completely different name...
So far, I see a very non transparent redirect to something having nothing in common with the name you're trying to fetch. This looks very sketchy at best. Expect no help from me until you actually explain what you want to do in explicit terms. It looks like you're trying to pull a fast one on pkg_add, and obviously pkg_add isn't duped... you tell it you want to install something, and you end up grabbing some other thing. No way !
