If the CLI tool needs to access arbitrary data from your home directory, then it is you. There is no security boundary between you and another user with full ac

If the CLI tool needs to access arbitrary data from your home directory, then it is you. There is no security boundary between you and another user with full access to everything you own. If you want to share specific directories, you can just put the shared directory in a common location, set it to be owned by some group, and make both users a member of that group. I don't see anything not-straightforward in there?