A reply another app can read
A support app might ask AI to sort a customer message. Instead of a paragraph, the model returns labelled fields for the category, urgency, and a short explanation. A schema says which fields must appear and what values are allowed.
The format can be right while the answer is wrong
A reply can use every required field and still put a message in the wrong category or invent an explanation. The app must check the details and permissions before acting on it.
If the format changes, software that reads it may need updating too.