The -n flag tells ssh to only make a connection, without ever running a shell. This means it even works when you don't have shell access (say, with a command= entry in .authorized_keys).
Also, I cannot recommend envoy enough in lieu of ssh-agent, if you're not using a GUI ssh agent already (e.g OSX keychain or GNOME keyring)
Last, I guarantee you don't want "$@" in those aliases, but either "$*" or $@ (certainly the latter).
I think you meant -N, not -n. From the man page[1]:
-N Do not execute a remote command. This is useful for just for‐
warding ports (protocol version 2 only).
-n Redirects stdin from /dev/null (actually, prevents reading from
stdin). This must be used when ssh is run in the background.
I usually visit these threads knowing that I will pick up something useful to add to the toolbox... thank you for 'envoy' - I think it will streamline my ssh key management.
Also, I cannot recommend envoy enough in lieu of ssh-agent, if you're not using a GUI ssh agent already (e.g OSX keychain or GNOME keyring)
Last, I guarantee you don't want "$@" in those aliases, but either "$*" or $@ (certainly the latter).