raising an error when the authentication field is present in the authorization field and in the header

src/llama_stack/providers/inline/agents/meta_reference/responses/streaming.py

@@ -1082,11 +1082,15 @@ class StreamingResponseOrchestrator:
             # Prepare headers with authorization from tool config
             headers = dict(mcp_tool.headers or {})
             if mcp_tool.authorization:
-                # Don't override existing Authorization header (case-insensitive check)
+                # Check if Authorization header already exists (case-insensitive check)
                 existing_keys_lower = {k.lower() for k in headers.keys()}
-                if "authorization" not in existing_keys_lower:
+                if "authorization" in existing_keys_lower:
-                    # OAuth access token - add "Bearer " prefix
+                    raise ValueError(
-                    headers["Authorization"] = f"Bearer {mcp_tool.authorization}"
+                        "Cannot specify Authorization in both 'headers' and 'authorization' fields. "
+                        "Please use only the 'authorization' field."
+                    )
+                # OAuth access token - add "Bearer " prefix
+                headers["Authorization"] = f"Bearer {mcp_tool.authorization}"
 
             async with tracing.span("list_mcp_tools", attributes):
                 tool_defs = await list_mcp_tools(

src/llama_stack/providers/inline/agents/meta_reference/responses/tool_executor.py

@@ -302,11 +302,15 @@ class ToolExecutor:
                 # Prepare headers with authorization from tool config
                 headers = dict(mcp_tool.headers or {})
                 if mcp_tool.authorization:
-                    # Don't override existing Authorization header (case-insensitive check)
+                    # Check if Authorization header already exists (case-insensitive check)
                     existing_keys_lower = {k.lower() for k in headers.keys()}
-                    if "authorization" not in existing_keys_lower:
+                    if "authorization" in existing_keys_lower:
-                        # OAuth access token - add "Bearer " prefix
+                        raise ValueError(
-                        headers["Authorization"] = f"Bearer {mcp_tool.authorization}"
+                            "Cannot specify Authorization in both 'headers' and 'authorization' fields. "
+                            "Please use only the 'authorization' field."
+                        )
+                    # OAuth access token - add "Bearer " prefix
+                    headers["Authorization"] = f"Bearer {mcp_tool.authorization}"
 
                 async with tracing.span("invoke_mcp_tool", attributes):
                     result = await invoke_mcp_tool(
@@ -369,7 +373,6 @@ class ToolExecutor:
                 mcp_completed_event = OpenAIResponseObjectStreamResponseMcpCallCompleted(
                     sequence_number=sequence_number,
                 )
-                yield ToolExecutionResult(stream_event=mcp_completed_event, sequence_number=sequence_number)
         elif function_name == "web_search":
             sequence_number += 1
             web_completion_event = OpenAIResponseObjectStreamResponseWebSearchCallCompleted(
@@ -485,6 +488,8 @@ class ToolExecutor:
             input_message = OpenAIToolMessageParam(content=msg_content, tool_call_id=tool_call_id)  # type: ignore[arg-type]
         else:
             text = str(error_exc) if error_exc else "Tool execution failed"
-            input_message = OpenAIToolMessageParam(content=text, tool_call_id=tool_call_id)
+            input_message = OpenAIToolMessageParam(
+                content=text, tool_call_id=tool_call_id
+            )
 
         return message, input_message

tests/integration/responses/test_mcp_authentication.py

@@ -91,40 +91,36 @@ def test_mcp_authorization_different_token(compat_client, text_model_id):
         assert response.output[1].error is None
 
 
-def test_mcp_authorization_fallback_to_headers(compat_client, text_model_id):
+def test_mcp_authorization_error_when_both_provided(compat_client, text_model_id):
-    """Test that authorization parameter doesn't override existing Authorization header."""
+    """Test that providing both headers['Authorization'] and authorization field raises an error."""
     if not isinstance(compat_client, LlamaStackAsLibraryClient):
         pytest.skip("in-process MCP server is only supported in library client")
 
-    # Headers should take precedence - this test uses headers auth
+    test_token = "test-token-123"
-    test_token = "headers-token-123"
     with make_mcp_server(required_auth_token=test_token) as mcp_server_info:
         tools = setup_mcp_tools(
             [
                 {
                     "type": "mcp",
-                    "server_label": "headers-mcp",
+                    "server_label": "both-auth-mcp",
                     "server_url": "<FILLED_BY_TEST_RUNNER>",
                     "headers": {"Authorization": f"Bearer {test_token}"},
-                    "authorization": "should-not-override",  # Just the token
+                    "authorization": "should-cause-error",  # This should trigger an error
                 }
             ],
             mcp_server_info,
         )
 
-        # Create response - headers should take precedence
+        # Create response - should raise ValueError
-        response = compat_client.responses.create(
+        with pytest.raises(
-            model=text_model_id,
+            ValueError, match="Cannot specify Authorization in both 'headers' and 'authorization' fields"
-            input="What is the boiling point of myawesomeliquid?",
+        ):
-            tools=tools,
+            compat_client.responses.create(
-            stream=False,
+                model=text_model_id,
-        )
+                input="What is the boiling point of myawesomeliquid?",
-
+                tools=tools,
-        # Verify operations succeeded with headers auth
+                stream=False,
-        assert len(response.output) >= 3
+            )
-        assert response.output[0].type == "mcp_list_tools"
-        assert response.output[1].type == "mcp_call"
-        assert response.output[1].error is None
 
 
 def test_mcp_authorization_backward_compatibility(compat_client, text_model_id):