Please read this first

• Have you read the docs?Agents SDK docs -> yes
• Have you searched for related issues? Others may have faced similar issues. -> Yes

Describe the bug

When I configure the set_default_openai_api("chat_completions") in the OpenAI Agents SDK, the traces rendered in the UI switch from a well-formatted Markdown view to a raw JSON format. This behavior does not occur when using the default responses API.

Debug information

• Agents SDK version: v0.0.9
• Python version (e.g. Python 3.13)

Repro steps

...

def get_azure_openai_client():
    """
    Creates and returns an Azure OpenAI client instance.
    
    Returns:
        AsyncAzureOpenAI: Configured Azure OpenAI client
    """
    load_dotenv()
    
    return AsyncAzureOpenAI(
        api_key=os.getenv("AZURE_OPENAI_API_KEY"),
        api_version=os.getenv("AZURE_OPENAI_API_VERSION"),
        azure_endpoint=os.getenv("AZURE_OPENAI_ENDPOINT"),
    )


openai_client = get_azure_openai_client()
set_default_openai_client(openai_client, use_for_tracing=False)
set_default_openai_api("chat_completions")  # 👈 Switching to this causes the trace format change

...

rag_agent = Agent(
    name="rag_agent",
    instructions=PROMPT,
    tools=[get_stocks_information, get_current_datetime],
    model=os.getenv("AZURE_OPENAI_GPT_4O_MODEL"),
    model_settings=ModelSettings(
        temperature=0,
        parallel_tool_calls=True,
        max_tokens=4096,
    ),
    input_guardrails=[smartsource_input_guardrail],
)

✅ Responses API (Expected Trace View)

❌ Chat Completions API (Raw JSON Trace)

Expected behavior

The trace output should remain consistent in terms of formatting and readability regardless of whether I use chat_completions or responses. Ideally, both should render structured, human-readable output (e.g., Markdown or rich display), especially since the underlying content remains similar.

Notes
• The model used in both cases is GPT-4o from Azure.
• This may be a regression or an unhandled case in the tracing renderer.
• If this is the expected behavior, are there plans to provide consistent trace formatting across APIs?

@rm-openai Please help! :)