This tool runs during derivation and adds Higgs STXS truth information to the AOD.
To run it requires the TruthConverters package that was not yet in the release.
Additionally I had to make a couple of modifications to the HiggsTruthCategoryTool which is only used by this tool.
I was able to successfully run on a Higgs AOD with this enabled as part of PHYS and the results looked reasonable.