It took me a fair bit of trial and error to work out the exact magic words to say to get google maps to launch navigation to a given address by car without requiring me to use the touch screen at all.
My natural inclination was to say "Hey Google, give me directions to 123 fake street" but this would bring up a route (or if you're especially unlucky a list of different places for you to choose from) but require you to press a "start" button with your finger, and often also require you to switch the navigation type from bus/walk/cycle to car manually too.
"Give me directions to 123 fake street by car" would skip the navigation type selection, but still require you to manually press a "start" button (various variations of "ok google, begin" or "ok google, start" etc didn't seem to do anything")
After a long period (months) of having to press a tiny button manually while driving to start navigation I finally discovered that if you say "Navigate to" rather than "Give me directions to" it would skip past the start button screen and jump straight to giving you directions.
So now it works great, but I hope I don't have to go through tedious trial and error with everything voice activated to work out the exact phrasing it wants.
All of these commands printed out on a list somewhere would probably be consistent, and make sense. But you don't get to see that list. Google and others want to present these systems as magical AI helpers that you just converse with, as if they had any more intelligence than a touch tone menu system circa 1990.
Knowing how these things work, it just strikes me as hubris. The UX isn't good because they can't admit that the whole system isn't as good as they say it is or want it to be, and this makes them opaque and frustrating to interact with.
What we have nowadays is more like a voice-input command line, with all of the stiltedness and attention to detail when crafting your input that requires.
Unfortunately people want to pretend that natural language parsing can be solved, which, at least, for English is impossible: https://en.wikipedia.org/wiki/Time_flies_like_an_arrow;_frui...
I must be officially old, because I see no reason to give voice commands to things. If I did I'd just attach a microphone to the server I run at home and connect it to things.