A link to the latest or(and) a debian repository.

[jringoot]

Your idea

A repository or a default location for the latest stable version would make automatic installation/upgrade of the client a lot easier.
I actually would prefer an apt repository, then it can be sheduled as unattended upgrade.
https://wiki.debian.org/UnattendedUpgrades

[jringoot]

this should do it

export TAG=`curl -s https://api.github.com/repos/glpi-project/glpi-agent/releases/latest | grep tag_name | cut -d \" -f 4`
wget https://github.com/glpi-project/glpi-agent/releases/download/$TAG/glpi-agent-$TAG-linux-installer.pl
sudo perl ./glpi-agent-$TAG-linux-installer.pl -s $inventory-server
 sudo glpi-agent