Update GPT model reference and clarify supported models...

...for the Deep Research tool in deep-research.md

Author: sanjeev3

articles/ai-foundry/agents/how-to/tools/deep-research.md

@@ -47,11 +47,14 @@ The Deep Research tool is supported in the following regions where the deep rese
 |---------|---------|
 | ✔️ | ✔️ | 
 
-## GPT model for clarifying research scope
+## GPT-4o model for clarifying research scope
 
-The Deep Research tool uses a GPT model to clarify the question contained in the user prompt, gather additional context if needed, and precisely scope the research task. This model is deployed during configuration of the Deep Research tool and can be one of the GPT-series models including GPT-4o, **except** the GPT-4.1 family, The 4.1 family is not supported by the Agents service.
+The Deep Research tool uses the **`gpt-4o`** model to clarify the question contained in the user prompt, gather additional context if needed, and precisely scope the research task. This model is deployed during configuration of the Deep Research tool. 
 
-## Deep research model for deep analysis
+> [!NOTE]
+> Other GPT-series models including GPT-4o-mini and the GPT-4.1 family are not supported for scope clarification.
+
+## Deep research model for analysis
 
 - **Model name**: `o3-deep-research`
 - **Deployment type**: Global Standard