How do I get my voice agent to read phone numbers and addresses back correctly?

Add a short instruction to the prompt. For phone numbers, tell it: anytime you repeat the phone number, say it one digit at a time separated by commas, and give an example of exactly how you want it spoken. Without that, the agent may say the number in groups, such as seven fourteen.

For addresses, tell it to ask for the full street address, then spell back the street number and street name and confirm they are correct. You can tell it not to spell out the city.