fix(gemini): support snake_case for google_search tool parameters (#18451)

* fix(gemini): support snake_case for google_search tool parameters

Add snake_case aliases for Gemini tool names to match the pattern
already used by other tools (url_context, google_maps, code_execution):
- google_search -> googleSearch
- google_search_retrieval -> googleSearchRetrieval
- enterprise_web_search -> enterpriseWebSearch

* test(gemini): add tests for snake_case google_search tool aliases

* refactor(gemini): simplify get_tool_value calls formatting

litellm/llms/vertex_ai/gemini/vertex_and_google_ai_studio_gemini.py

@@ -480,20 +480,21 @@ class VertexGeminiConfig(VertexAIBaseConfig, BaseConfig):
                 or tool_name == VertexToolName.CODE_EXECUTION.value
             ):  # code_execution maintained for backwards compatibility
                 code_execution = self.get_tool_value(tool, "codeExecution")
-            elif tool_name and tool_name == VertexToolName.GOOGLE_SEARCH.value:
-                googleSearch = self.get_tool_value(
-                    tool, VertexToolName.GOOGLE_SEARCH.value
-                )
-            elif (
-                tool_name and tool_name == VertexToolName.GOOGLE_SEARCH_RETRIEVAL.value
+            elif tool_name and (
+                tool_name == VertexToolName.GOOGLE_SEARCH.value
+                or tool_name == "google_search"
             ):
-                googleSearchRetrieval = self.get_tool_value(
-                    tool, VertexToolName.GOOGLE_SEARCH_RETRIEVAL.value
-                )
-            elif tool_name and tool_name == VertexToolName.ENTERPRISE_WEB_SEARCH.value:
-                enterpriseWebSearch = self.get_tool_value(
-                    tool, VertexToolName.ENTERPRISE_WEB_SEARCH.value
-                )
+                googleSearch = self.get_tool_value(tool, tool_name)
+            elif tool_name and (
+                tool_name == VertexToolName.GOOGLE_SEARCH_RETRIEVAL.value
+                or tool_name == "google_search_retrieval"
+            ):
+                googleSearchRetrieval = self.get_tool_value(tool, tool_name)
+            elif tool_name and (
+                tool_name == VertexToolName.ENTERPRISE_WEB_SEARCH.value
+                or tool_name == "enterprise_web_search"
+            ):
+                enterpriseWebSearch = self.get_tool_value(tool, tool_name)
             elif tool_name and (
                 tool_name == VertexToolName.URL_CONTEXT.value
                 or tool_name == "urlContext"

tests/litellm/llms/vertex_ai/gemini/test_transformation.py

@@ -7,6 +7,7 @@ sys.path.insert(
     0, os.path.abspath("../../../../..")
 )  # Adds the parent directory to the system path
 from litellm.llms.vertex_ai.gemini import transformation
+from litellm.llms.vertex_ai.gemini.vertex_and_google_ai_studio_gemini import VertexGeminiConfig
 from litellm.types.llms import openai
 from litellm.types import completion
 from litellm.types.llms.vertex_ai import RequestBody
@@ -225,4 +226,65 @@ async def test__transform_request_body_image_config_with_image_size():
     assert "generationConfig" in rb
     assert "imageConfig" in rb["generationConfig"]
     assert rb["generationConfig"]["imageConfig"]["aspectRatio"] == "16:9"
-    assert rb["generationConfig"]["imageConfig"]["imageSize"] == "4K"
+    assert rb["generationConfig"]["imageConfig"]["imageSize"] == "4K"
+
+
+def test_map_function_google_search_snake_case():
+    """
+    Test that google_search tool (snake_case) is properly mapped to googleSearch.
+    Fixes issue where tools=[{"google_search": {}}] was being stripped.
+    """
+    config = VertexGeminiConfig()
+    optional_params = {}
+
+    # Test snake_case google_search
+    tools = [{"google_search": {}}]
+    result = config._map_function(tools, optional_params)
+
+    assert len(result) == 1
+    assert "googleSearch" in result[0]
+    assert result[0]["googleSearch"] == {}
+
+
+def test_map_function_google_search_camel_case():
+    """
+    Test that googleSearch tool (camelCase) still works.
+    """
+    config = VertexGeminiConfig()
+    optional_params = {}
+
+    # Test camelCase googleSearch
+    tools = [{"googleSearch": {}}]
+    result = config._map_function(tools, optional_params)
+
+    assert len(result) == 1
+    assert "googleSearch" in result[0]
+    assert result[0]["googleSearch"] == {}
+
+
+def test_map_function_google_search_retrieval_snake_case():
+    """
+    Test that google_search_retrieval tool (snake_case) is properly mapped.
+    """
+    config = VertexGeminiConfig()
+    optional_params = {}
+
+    tools = [{"google_search_retrieval": {"dynamic_retrieval_config": {"mode": "MODE_DYNAMIC"}}}]
+    result = config._map_function(tools, optional_params)
+
+    assert len(result) == 1
+    assert "googleSearchRetrieval" in result[0]
+
+
+def test_map_function_enterprise_web_search_snake_case():
+    """
+    Test that enterprise_web_search tool (snake_case) is properly mapped.
+    """
+    config = VertexGeminiConfig()
+    optional_params = {}
+
+    tools = [{"enterprise_web_search": {}}]
+    result = config._map_function(tools, optional_params)
+
+    assert len(result) == 1
+    assert "enterpriseWebSearch" in result[0]