How to write command line tools with a good user experience
Write a specification and get nested subcommands, option and parameter specification and validation, help, documentation, and advanced shell tab completion.
Good commandline tools
* give good usage error messages
* have good usage output
* have useful shell tab completion
* have good man pages
Your CLI framework should do that work for you, and you should not have to write duplicate code/pod.
I'll show a framework that tries to implement all these things, and some examples to demonstrate how advanced completion can make the life of your users much easier.