Update responses.md

Author: mrbullwinkle

articles/ai-services/openai/how-to/responses.md

@@ -5,7 +5,7 @@ description: Learn how to use Azure OpenAI's new stateful Responses API.
 manager: nitinme
 ms.service: azure-ai-openai
 ms.topic: include
-ms.date: 03/07/2025
+ms.date: 03/21/2025
 author: mrbullwinkle    
 ms.author: mbullwin
 ms.custom: references_regions
@@ -44,6 +44,12 @@ The responses API is currently available in the following regions:
 - `gpt-4o-mini`
 - `computer-use-preview`
 
+> [!NOTE]
+> The responses API does not currently support:
+>  - Structured outputs
+>  - tool_choice
+>  Once support is added this article will be updated.
+
 ## Getting started with the responses API
 
 To access the responses API commands, you need to upgrade your version of the OpenAI library.
@@ -1462,4 +1468,4 @@ async def main():
 
 if __name__ == "__main__":
     asyncio.run(main())
-```
+```