I have raised that already as feature request.
https://community.home-assistant.io/t/where-do-descriptions-for-shell-commands-go/216725
I am really wondering how one should remember what parameters to be used for shell commands that were created months ago or even maybe what they are doing?
I have to take note about this in my old fashioned paper & pencil notebook when I created a shell_command ?!? 
Having a services.yaml equivalent to python_scripts would be wonderful 