It would be nice if a couple of additional environment variables to be set for hook uses.
GIT_ANNEX_DIRECT=`git config annex.direct`
GIT_TOP_LEVEL=`git rev-parse --show-toplevel`
I've made some changes to flickrannex to allow the sub-directories above the uploaded image to be added as tags. This change has been merged into trunk: https://github.com/TobiasTheViking/flickrannex
What I needed was both the environment variables mentioned above. One is set as part of the annex-hook and the other I guestimate from the file path. If it was set in git-annex it would be much cleaner (and accurate). So...I think this info would be useful for other hook.