OtherDrops (probably due to Bukkit-limitations) cannot recognise tools from mods as tools. For instance, if I have a scythe-tool from a mod, the damagetool parameter will not work with this item because OtherDrops does not recognise it as a tool.

I was wondering if there could be a flag of some sort that forces damagetool to add +1 to the damage value of an item, regardless of whether it is a tool or not. That would leave another issue of preventing tools from being used when they're supposed to break, but I suppose a user-sided workaround would be to specify the acceptable range of damage values on an item (i.e. tool: SCYTHE@0-127).