We are all experts at human-to-human conversation. But conversing only seems easy because it’s familiar, you’ve been doing it since you were born. The key to building a good voice interface is to not fall into the trap of simply converting a GUI into a VUI.
In the slides below, I will cover the best practices to design our Action on Google (and any other Voice UI).
You can also see the top tips in the short video below.
Last but not least, if you wish to improve your current design, check this post.
Be wise.
Ido Green 
Here is another way of how to design for voice user interface >>https://www.cygnismedia.com/blog/how-to-design-voice-user-interfaces/