diff --git a/litellm/llms/vertex_ai/gemini/vertex_and_google_ai_studio_gemini.py b/litellm/llms/vertex_ai/gemini/vertex_and_google_ai_studio_gemini.py
index b70f4295d3b..7ee32260fe0 100644
--- a/litellm/llms/vertex_ai/gemini/vertex_and_google_ai_studio_gemini.py
+++ b/litellm/llms/vertex_ai/gemini/vertex_and_google_ai_studio_gemini.py
@@ -2289,14 +2289,6 @@ class VertexGeminiConfig(VertexAIBaseConfig, BaseConfig):
                     is_function_call=is_function_call(standard_optional_params),
                 )
 
-            # Outside the "content"/"parts" branch on purpose. Gemini does not
-            # promise to put groundingMetadata on a chunk that also carries text:
-            # streaming commonly delivers it on the final candidate, which has a
-            # finishReason and no parts at all. Converting only when parts were
-            # present dropped the citations for exactly those responses, which is
-            # why the same prompt produced annotations on some runs and not
-            # others while non-streaming -- one candidate, always with parts --
-            # produced them every time.
             if candidate_grounding_metadata:
                 annotations = VertexGeminiConfig._convert_grounding_metadata_to_annotations(
                     grounding_metadata=candidate_grounding_metadata,
diff --git a/tests/unit/llms/vertex_ai/gemini/test_vertex_and_google_ai_studio_gemini.py b/tests/unit/llms/vertex_ai/gemini/test_vertex_and_google_ai_studio_gemini.py
index 393732bb12a..86c0ab49414 100644
--- a/tests/unit/llms/vertex_ai/gemini/test_vertex_and_google_ai_studio_gemini.py
+++ b/tests/unit/llms/vertex_ai/gemini/test_vertex_and_google_ai_studio_gemini.py
@@ -6376,7 +6376,7 @@ _GROUNDING_URIS: Final = [
 ]
 
 
-def _gemini_stream_iterator():
+def _gemini_stream_iterator() -> "ModelResponseIterator":
     from litellm.llms.vertex_ai.gemini.vertex_and_google_ai_studio_gemini import ModelResponseIterator
 
     logging_obj = MagicMock()
@@ -6384,8 +6384,8 @@ def _gemini_stream_iterator():
     return ModelResponseIterator(streaming_response=iter([]), sync_stream=True, logging_obj=logging_obj)
 
 
-def _delta_annotations(model_response):
-    found: list = []
+def _delta_annotations(model_response: object) -> List[dict]:
+    found: List[dict] = []
     for choice in model_response.choices:
         annotations = getattr(getattr(choice, "delta", None), "annotations", None)
         if annotations:
@@ -6393,12 +6393,11 @@ def _delta_annotations(model_response):
     return found
 
 
-def _citation_urls(annotations):
+def _citation_urls(annotations: List[dict]) -> List[str]:
     return [annotation["url_citation"]["url"] for annotation in annotations]
 
 
-def test_streaming_grounding_on_the_final_chunk_produces_annotations():
-    """Gemini often sends groundingMetadata on a candidate with finishReason and no parts"""
+def test_streaming_grounding_on_the_final_chunk_produces_annotations() -> None:
     iterator = _gemini_stream_iterator()
     iterator.chunk_parser({"candidates": [{"index": 0, "content": {"role": "model", "parts": [{"text": _GROUNDED_TEXT}]}}]})
 
@@ -6409,8 +6408,7 @@ def test_streaming_grounding_on_the_final_chunk_produces_annotations():
     assert _citation_urls(_delta_annotations(final)) == _GROUNDING_URIS
 
 
-def test_streaming_grounding_alongside_text_produces_annotations():
-    """The shape that already worked keeps working"""
+def test_streaming_grounding_alongside_text_produces_annotations() -> None:
     iterator = _gemini_stream_iterator()
 
     chunk = iterator.chunk_parser(
@@ -6432,7 +6430,7 @@ def test_streaming_grounding_alongside_text_produces_annotations():
     assert annotations[0]["url_citation"]["start_index"] == 0
 
 
-def test_streaming_without_grounding_carries_no_annotations():
+def test_streaming_without_grounding_carries_no_annotations() -> None:
     iterator = _gemini_stream_iterator()
 
     chunk = iterator.chunk_parser(
@@ -6442,8 +6440,7 @@ def test_streaming_without_grounding_carries_no_annotations():
     assert _delta_annotations(chunk) == []
 
 
-def test_streaming_grounding_without_web_chunks_carries_no_annotations():
-    """Maps grounding has no web URI to cite, so it must not invent one"""
+def test_streaming_grounding_without_web_chunks_carries_no_annotations() -> None:
     iterator = _gemini_stream_iterator()
 
     chunk = iterator.chunk_parser(
@@ -6466,7 +6463,7 @@ def test_streaming_grounding_without_web_chunks_carries_no_annotations():
     assert _delta_annotations(chunk) == []
 
 
-def test_non_streaming_grounding_annotations_are_unchanged():
+def test_non_streaming_grounding_annotations_are_unchanged() -> None:
     model_response = ModelResponse()
     VertexGeminiConfig._process_candidates(
         [
@@ -6485,8 +6482,7 @@ def test_non_streaming_grounding_annotations_are_unchanged():
     assert _citation_urls(annotations or []) == _GROUNDING_URIS
 
 
-def test_streamed_grounding_survives_reassembly():
-    """A client rebuilding the stream ends up with the citations a non-streaming call returns"""
+def test_streamed_grounding_survives_reassembly() -> None:
     iterator = _gemini_stream_iterator()
     chunks = [
         iterator.chunk_parser(