My sense of discovery was meant in the UI sort of respect. When a feature is hidden from the user, that feature might as well not exist.

Bots (and command lines, for that matter) are awful unless you know exactly what they're capable of. There is an extrinsic knowledge you need.

That is, you can't expect a bot to know whatever you throw at it but you're unsure what you /can/ expect it to know.

The problem is that command lines are sort of made for the expert users whereas bots are said to be the opposite.