Thanks, brenden dv,
I'm not looking to create a more advanced shortcut, but to add more available actions to the actions list. For example, I have a Philips Hue hub and the Hue app for my phone to be able to control the lights connected to the hub. Out of all the lights that I have, there are only a couple of actions listed, both to turn particular lights off. I'd like to create an action to turn on or off lights that aren't listed in the actions, and there doesn't seem to be a way to do that.
I'm not sure how the actions got there to begin with. Siri doesn't seem to know either. "Siri, create an action," doesn't seem to be something she knows. I suspect that this feature doesn't exist and that something in iOS arbitrarily creates them, which makes creating shortcuts and automatons not terrifically useful at the moment. Perhaps the thing for me to do is to utilize the feedback link you've provided.
I appreciate your response.