pkgver is the version of the package, but it's generated automatically after getting the source in the pkgver function anyway.
The guidelines are here: https://wiki.archlinux.org/index.php/VCS_PKGBUILD_Guidelines#Git
It might be better to use ````echo $(git rev-list --count HEAD).$(git rev-parse --short HEAD)```` instead of ````git describe --always | sed 's|-|.|g'````, not sure.