1. Google Assistant doesn’t allow any actions which lead to any transactions websites(like ordering, buying, purchasing, booking).
2. Make sure your conversation flow doesn’t break or must relevant conversation.
3. Please make sure that the descriptions you are providing for your app must contain information on what your app is about as well as some of the functionality it can complete. For eg:- If your app has subscription or feedback feature describe it. 
4. Please make sure that your app icon is not associated with a well-known brand.
5. Please make sure that your conversation doesn’t spam users by including excessive low quality or duplicative content.
6. Please make sure that your app doesn’t collect any personal information from users outside the app like name and phone number, which does not comply with Google Assistant policies.
7. Please make sure the privacy policy URL which you are providing must link to a valid website containing a privacy policy specific to your app.
8. Please make sure that your conversation doesn’t contain any content which includes pornographic, erotic, sexual acts.
9. Make Sure your conversation doesn’t contain any child sexual abuse content.