The solution to that problem will be AI to AI instead of AI to human, using standardized interfacing (likely one of a few big common standards, with each AI being capable of utilizing any of them) so the AI can easily understand each other.
In the next ten years there will be a large battle - which will play out on HN daily - over the AI to AI standards; it'll remind older developers of the XML / JSON days.
The beginning of the chain is a human -- the user! And at the end of the day this is all about the user!
Once you know what the user wants it's "easy" (well, somewhat easy anyway :-). It's the iterative process of understanding the user in an unconstrained opaque ad hoc UI that is big-H Hard.
The problem with these spoken interfaces is not just that we don't know what we don't know, we don't even know what we want to accomplish!
In the next ten years there will be a large battle - which will play out on HN daily - over the AI to AI standards; it'll remind older developers of the XML / JSON days.