> like there is for CLIs where you can do something like

Well, these will fail for a large amount of cli tools. Any and all combinations of the following are possible, and not all of them will be available, or work at all:

    tool                    some tools may output usage when no arguments are supplied
    tool -h                 some tools may have a short switch for help
    tool --help             some tools may have a long switch for help
    tool help               some tools may have help as a subcommand
    tool command            some tools may output usage for a command with no arguments
    tool command -h         some tools may have a short switch for command help
    tool command --help     some tools may have a long switch for command help
    tool help command       some tools may have a help command
    man tool                some tools may have man pages
    

examples:

    grep                    one-line usage and "type grep --help"
    grep -h                 one-line usage and "type grep --help"
    grep --help             extended usage docs
    man grep                very extended usage docs


    python                  starts interactive python shell
    python -h
    python --help           equivalent help output


    ps                      short list of processes
    ps -h                   longer list of processes
    ps --help               short help saying you can do, for example, `ps --help a`
    ps --help a             gives an extended help, nothing about a

    erl                     
    erl -h
    erl --help              all three start Erlang shell
    man erl                 No manual entry for erl

etc.

Not to say that MCPs are any better. They are written by people, after all. So they are as messy.