Julia Evans had an interesting thread recently on “social rules” of the terminal: https://social.jvns.ca/@b0rk/113540676612640547

This is a good, open-source resource for guidelines on creating CLIs, which goes over some common mistakes.

https://clig.dev/

These days: not building this such that they can be easily spit out as json and/or xml markup.

Not obeying the --help flag.

not behaving the same as robust cli tools. -h and --help and -v and --verbose and --version