diff --git a/litellm/responses/litellm_completion_transformation/transformation.py b/litellm/responses/litellm_completion_transformation/transformation.py
index 35d4b8bf1ba..88875a049d1 100644
--- a/litellm/responses/litellm_completion_transformation/transformation.py
+++ b/litellm/responses/litellm_completion_transformation/transformation.py
@@ -2120,7 +2120,7 @@ class LiteLLMCompletionResponsesConfig:
                     # Ensure we include any accumulated text as text blocks too
                     return normalized_blocks
                 if text_acc:
-                    return "".join(text_acc)
+                    return "\n".join(text_acc)
                 try:
                     # last resort: keep something meaningful for providers that require a string
                     import json as _json
diff --git a/tests/unit/responses/litellm_completion_transformation/test_function_call_output_normalization.py b/tests/unit/responses/litellm_completion_transformation/test_function_call_output_normalization.py
index 3af1ef51e3e..1a0b8d34ee0 100644
--- a/tests/unit/responses/litellm_completion_transformation/test_function_call_output_normalization.py
+++ b/tests/unit/responses/litellm_completion_transformation/test_function_call_output_normalization.py
@@ -11,7 +11,26 @@ from litellm.responses.litellm_completion_transformation.transformation import (
 )
 
 
-def test_function_call_output_list_input_text_is_converted_to_tool_string_content():
+def test_function_call_output_list_input_text_parts_reach_the_tool_message_on_separate_lines():
+    out = LiteLLMCompletionResponsesConfig._transform_responses_api_tool_call_output_to_chat_completion_message(
+        tool_call_output={
+            "type": "function_call_output",
+            "call_id": "call_1",
+            "output": [
+                {"type": "input_text", "text": "Paris: 22 degrees"},
+                {"type": "input_text", "text": "clear skies"},
+            ],
+        }
+    )
+
+    assert len(out) == 1
+    msg = out[0]
+    assert msg["role"] == "tool"
+    assert msg["tool_call_id"] == "call_1"
+    assert msg["content"] == "Paris: 22 degrees\nclear skies"
+
+
+def test_function_call_output_text_part_whitespace_survives_the_join():
     out = LiteLLMCompletionResponsesConfig._transform_responses_api_tool_call_output_to_chat_completion_message(
         tool_call_output={
             "type": "function_call_output",
@@ -23,11 +42,7 @@ def test_function_call_output_list_input_text_is_converted_to_tool_string_conten
         }
     )
 
-    assert len(out) == 1
-    msg = out[0]
-    assert msg["role"] == "tool"
-    assert msg["tool_call_id"] == "call_1"
-    assert msg["content"] == "hello world"
+    assert out[0]["content"] == "hello\n world"
 
 
 def test_function_call_output_string_passthrough():