You have to specify the schema for that regardless. Function calling has been available for text inputs for awhile, now it's also available for image inputs. O

You have to specify the schema for that regardless. Function calling has been available for text inputs for awhile, now it's also available for image inputs. OpenAI's function calling/structured data mode is much more strict and reliable at following the schema than just putting "return the output in JSON" in a system prompt.