Good scissors seem to obviously fit into the "Tools, devices, and appliances that efficiently perform a useful function" category, so I'm not sure what to do wi

Good scissors seem to obviously fit into the "Tools, devices, and appliances that efficiently perform a useful function" category, so I'm not sure what to do with your specific example. I can't easily come up with examples of items which don't fit the taxonomy that my beneficiaries would nonetheless appreciate receiving in my will, and I think "if I don't want it my grandkids definitely won't" is a pretty good rule of thumb here.