Revert "fix(vertex): skip harmful schema transforms for Gemini 2.0+ tool parameters"

This reverts commit a9c3095cc5.

litellm/llms/vertex_ai/common_utils.py

@@ -520,28 +520,6 @@ def _build_vertex_schema(parameters: dict, add_property_ordering: bool = False):
     return parameters
 
 
-def _build_vertex_schema_for_gemini_2(parameters: dict) -> dict:
-    """
-    Minimal schema builder for Gemini 2.0+ tool parameters.
-
-    Gemini 2.0+ accepts standard JSON Schema natively in tool parameters,
-    including lowercase types, anyOf with null, and bare {} (TYPE_UNSPECIFIED).
-    The only transformation needed is resolving $ref/$defs, which Gemini does
-    NOT support in tool parameters (returns 400).
-
-    This avoids the harmful transforms in _build_vertex_schema that break
-    JsonValue/Any semantics by coercing {} to {"type": "object"}.
-    """
-    valid_schema_fields = set(get_type_hints(Schema).keys())
-
-    defs = parameters.pop("$defs", {})
-    unpack_defs(parameters, defs)
-
-    parameters = filter_schema_fields(parameters, valid_schema_fields)
-
-    return parameters
-
-
 def _build_json_schema(parameters: dict) -> dict:
     """
     Build a JSON Schema for use with Gemini's responseJsonSchema parameter.

litellm/llms/vertex_ai/gemini/vertex_and_google_ai_studio_gemini.py

@@ -97,7 +97,6 @@ from ..common_utils import (
     VertexAIError,
     _build_json_schema,
     _build_vertex_schema,
-    _build_vertex_schema_for_gemini_2,
     supports_response_json_schema,
 )
 from ..vertex_llm_base import VertexBase
@@ -468,7 +467,7 @@ class VertexGeminiConfig(VertexAIBaseConfig, BaseConfig):
             return None
 
     def _map_function(  # noqa: PLR0915
-        self, value: List[dict], optional_params: dict, model: str = ""
+        self, value: List[dict], optional_params: dict
     ) -> List[Tools]:
         """
         Map OpenAI-style tools/functions to Vertex AI format.
@@ -511,21 +510,10 @@ class VertexGeminiConfig(VertexAIBaseConfig, BaseConfig):
                     "parameters" in _openai_function_object
                     and _openai_function_object["parameters"] is not None
                     and isinstance(_openai_function_object["parameters"], dict)
-                ):
-                    if supports_response_json_schema(model):
-                        # Gemini 2.0+: minimal transform (resolve $ref only)
-                        _openai_function_object["parameters"] = (
-                            _build_vertex_schema_for_gemini_2(
-                                _openai_function_object["parameters"]
-                            )
-                        )
-                    else:
-                        # Gemini 1.5: full OpenAPI-style transform
-                        _openai_function_object["parameters"] = (
-                            _build_vertex_schema(
-                                _openai_function_object["parameters"]
-                            )
-                        )
+                ):  # OPENAI accepts JSON Schema, Google accepts OpenAPI schema.
+                    _openai_function_object["parameters"] = _build_vertex_schema(
+                        _openai_function_object["parameters"]
+                    )
 
                 openai_function_object = _openai_function_object
 
@@ -1063,7 +1051,7 @@ class VertexGeminiConfig(VertexAIBaseConfig, BaseConfig):
             ):
                 # Pass optional_params so _map_function can add toolConfig if needed
                 mapped_tools = self._map_function(
-                    value=value, optional_params=optional_params, model=model
+                    value=value, optional_params=optional_params
                 )
                 optional_params = self._add_tools_to_optional_params(
                     optional_params, mapped_tools

tests/test_litellm/llms/vertex_ai/test_vertex_ai_common_utils.py

@@ -11,7 +11,6 @@ sys.path.insert(
 )  # Adds the parent directory to the system path
 
 from litellm.llms.vertex_ai.common_utils import (
-    _build_vertex_schema_for_gemini_2,
     _get_vertex_url,
     convert_anyof_null_to_nullable,
     get_vertex_location_from_url,
@@ -1403,93 +1402,3 @@ def test_add_object_type_does_not_add_type_when_anyof_present():
 
     # Verify type was not added (anyOf handles the type)
     assert "type" not in input_schema, "type should not be added when anyOf is present"
-
-
-class TestBuildVertexSchemaForGemini2:
-    """Tests for _build_vertex_schema_for_gemini_2 — minimal transform for Gemini 2.0+ tools."""
-
-    def test_jsonvalue_standalone_preserved(self):
-        """JsonValue (bare {}) should NOT be coerced to {"type": "object"}."""
-        schema = {
-            "type": "object",
-            "properties": {
-                "name": {"type": "string"},
-                "value": {},
-            },
-            "required": ["name", "value"],
-        }
-        result = _build_vertex_schema_for_gemini_2(schema)
-        assert result["properties"]["value"] == {}
-
-    def test_optional_jsonvalue_anyof_preserved(self):
-        """Optional[JsonValue] anyOf with null should be preserved, not converted to nullable."""
-        schema = {
-            "type": "object",
-            "properties": {
-                "name": {"type": "string"},
-                "value": {
-                    "anyOf": [
-                        {"type": "array", "items": {}},
-                        {},
-                        {"type": "null"},
-                    ]
-                },
-            },
-            "required": ["name"],
-        }
-        result = _build_vertex_schema_for_gemini_2(schema)
-        value_schema = result["properties"]["value"]
-        assert "anyOf" in value_schema
-        assert len(value_schema["anyOf"]) == 3
-        assert {"type": "null"} in value_schema["anyOf"]
-        assert {} in value_schema["anyOf"]
-
-    def test_ref_defs_resolved(self):
-        """$ref/$defs should be resolved since Gemini doesn't support them in tool params."""
-        schema = {
-            "type": "object",
-            "properties": {
-                "value": {"$ref": "#/$defs/JsonValue"},
-            },
-            "$defs": {"JsonValue": {}},
-        }
-        result = _build_vertex_schema_for_gemini_2(schema)
-        assert "$ref" not in result["properties"]["value"]
-        assert "$defs" not in result
-        assert result["properties"]["value"] == {}
-
-    def test_unsupported_fields_stripped(self):
-        """Fields not in Vertex Schema TypedDict should be removed."""
-        schema = {
-            "type": "object",
-            "properties": {
-                "name": {"type": "string", "additionalProperties": False},
-            },
-            "additionalProperties": False,
-            "$schema": "http://json-schema.org/draft-07/schema#",
-        }
-        result = _build_vertex_schema_for_gemini_2(schema)
-        assert "additionalProperties" not in result
-        assert "$schema" not in result
-
-    def test_no_type_coercion(self):
-        """Schemas without type should NOT have type: object added."""
-        schema = {
-            "type": "object",
-            "properties": {
-                "data": {"description": "Any data"},
-            },
-        }
-        result = _build_vertex_schema_for_gemini_2(schema)
-        assert "type" not in result["properties"]["data"]
-
-    def test_items_empty_preserved(self):
-        """items: {} should NOT be coerced to items: {"type": "object"}."""
-        schema = {
-            "type": "object",
-            "properties": {
-                "values": {"type": "array", "items": {}},
-            },
-        }
-        result = _build_vertex_schema_for_gemini_2(schema)
-        assert result["properties"]["values"]["items"] == {}