Custom order in index

I would like to define a custom order on the keys in an index. I tried to set the desired order in glossaries descriptions and names, but it doesn’t work (@ behaves differently than I expect). Can you suggest a good workaround?

Here is an MWE:

documentclass{article}
usepackage{glossaries}
usepackage{indextools}
newglossaryentry{foo}{name={1},description={foolongname}}
newglossaryentry{bar}{name={2},description={barlongname}}
makeindex[name=my]
begin{document}
    foo index[my]{glsname{foo}@foo}
    bar index[my]{glsname{bar}@bar}
    printindex[my]
end{document}