

I might be misunderstanding the question, so if you’re looking to make an existing android device you have work like this, please ignore the below.
Maybe a Google Nest Mini would do what you’re looking for? It’s definitely got the ability to be interacted with entirely verbally, but I guess the downside is a smaller selection of apps that do work with it (there is a list on the Google store of which apps it works with)
To be honest I think it’s the trailing full stop that does that. Over text I find that usually comes across like you’re trying to shut down the conversation (even when you’re not)