fix: add the missing required tool parameters for Anthropic models

Fixes #1692

PiperOrigin-RevId: 795125801

src/google/adk/models/anthropic_llm.py

@@ -216,25 +216,31 @@ def _update_type_string(value_dict: dict[str, Any]):
 def function_declaration_to_tool_param(
     function_declaration: types.FunctionDeclaration,
 ) -> anthropic_types.ToolParam:
+  """Converts a function declaration to an Anthropic tool param."""
   assert function_declaration.name
 
   properties = {}
-  if (
+  required_params = []
-      function_declaration.parameters
+  if function_declaration.parameters:
-      and function_declaration.parameters.properties
+    if function_declaration.parameters.properties:
-  ):
+      for key, value in function_declaration.parameters.properties.items():
-    for key, value in function_declaration.parameters.properties.items():
+        value_dict = value.model_dump(exclude_none=True)
-      value_dict = value.model_dump(exclude_none=True)
+        _update_type_string(value_dict)
-      _update_type_string(value_dict)
+        properties[key] = value_dict
-      properties[key] = value_dict
+    if function_declaration.parameters.required:
+      required_params = function_declaration.parameters.required
+
+  input_schema = {
+      "type": "object",
+      "properties": properties,
+  }
+  if required_params:
+    input_schema["required"] = required_params
 
   return anthropic_types.ToolParam(
       name=function_declaration.name,
       description=function_declaration.description or "",
-      input_schema={
+      input_schema=input_schema,
-          "type": "object",
-          "properties": properties,
-      },
   )
 
 

tests/unittests/models/test_anthropic_llm.py

@@ -20,6 +20,7 @@ from anthropic import types as anthropic_types
 from google.adk import version as adk_version
 from google.adk.models import anthropic_llm
 from google.adk.models.anthropic_llm import Claude
+from google.adk.models.anthropic_llm import function_declaration_to_tool_param
 from google.adk.models.llm_request import LlmRequest
 from google.adk.models.llm_response import LlmResponse
 from google.genai import types
@@ -96,6 +97,200 @@ def test_supported_models():
   assert models[1] == r"claude-.*-4.*"
 
 
+function_declaration_test_cases = [
+    (
+        "function_with_no_parameters",
+        types.FunctionDeclaration(
+            name="get_current_time",
+            description="Gets the current time.",
+        ),
+        anthropic_types.ToolParam(
+            name="get_current_time",
+            description="Gets the current time.",
+            input_schema={"type": "object", "properties": {}},
+        ),
+    ),
+    (
+        "function_with_one_optional_parameter",
+        types.FunctionDeclaration(
+            name="get_weather",
+            description="Gets weather information for a given location.",
+            parameters=types.Schema(
+                type=types.Type.OBJECT,
+                properties={
+                    "location": types.Schema(
+                        type=types.Type.STRING,
+                        description="City and state, e.g., San Francisco, CA",
+                    )
+                },
+            ),
+        ),
+        anthropic_types.ToolParam(
+            name="get_weather",
+            description="Gets weather information for a given location.",
+            input_schema={
+                "type": "object",
+                "properties": {
+                    "location": {
+                        "type": "string",
+                        "description": (
+                            "City and state, e.g., San Francisco, CA"
+                        ),
+                    }
+                },
+            },
+        ),
+    ),
+    (
+        "function_with_one_required_parameter",
+        types.FunctionDeclaration(
+            name="get_stock_price",
+            description="Gets the current price for a stock ticker.",
+            parameters=types.Schema(
+                type=types.Type.OBJECT,
+                properties={
+                    "ticker": types.Schema(
+                        type=types.Type.STRING,
+                        description="The stock ticker, e.g., AAPL",
+                    )
+                },
+                required=["ticker"],
+            ),
+        ),
+        anthropic_types.ToolParam(
+            name="get_stock_price",
+            description="Gets the current price for a stock ticker.",
+            input_schema={
+                "type": "object",
+                "properties": {
+                    "ticker": {
+                        "type": "string",
+                        "description": "The stock ticker, e.g., AAPL",
+                    }
+                },
+                "required": ["ticker"],
+            },
+        ),
+    ),
+    (
+        "function_with_multiple_mixed_parameters",
+        types.FunctionDeclaration(
+            name="submit_order",
+            description="Submits a product order.",
+            parameters=types.Schema(
+                type=types.Type.OBJECT,
+                properties={
+                    "product_id": types.Schema(
+                        type=types.Type.STRING, description="The product ID"
+                    ),
+                    "quantity": types.Schema(
+                        type=types.Type.INTEGER,
+                        description="The order quantity",
+                    ),
+                    "notes": types.Schema(
+                        type=types.Type.STRING,
+                        description="Optional order notes",
+                    ),
+                },
+                required=["product_id", "quantity"],
+            ),
+        ),
+        anthropic_types.ToolParam(
+            name="submit_order",
+            description="Submits a product order.",
+            input_schema={
+                "type": "object",
+                "properties": {
+                    "product_id": {
+                        "type": "string",
+                        "description": "The product ID",
+                    },
+                    "quantity": {
+                        "type": "integer",
+                        "description": "The order quantity",
+                    },
+                    "notes": {
+                        "type": "string",
+                        "description": "Optional order notes",
+                    },
+                },
+                "required": ["product_id", "quantity"],
+            },
+        ),
+    ),
+    (
+        "function_with_complex_nested_parameter",
+        types.FunctionDeclaration(
+            name="create_playlist",
+            description="Creates a playlist from a list of songs.",
+            parameters=types.Schema(
+                type=types.Type.OBJECT,
+                properties={
+                    "playlist_name": types.Schema(
+                        type=types.Type.STRING,
+                        description="The name for the new playlist",
+                    ),
+                    "songs": types.Schema(
+                        type=types.Type.ARRAY,
+                        description="A list of songs to add to the playlist",
+                        items=types.Schema(
+                            type=types.Type.OBJECT,
+                            properties={
+                                "title": types.Schema(type=types.Type.STRING),
+                                "artist": types.Schema(type=types.Type.STRING),
+                            },
+                            required=["title", "artist"],
+                        ),
+                    ),
+                },
+                required=["playlist_name", "songs"],
+            ),
+        ),
+        anthropic_types.ToolParam(
+            name="create_playlist",
+            description="Creates a playlist from a list of songs.",
+            input_schema={
+                "type": "object",
+                "properties": {
+                    "playlist_name": {
+                        "type": "string",
+                        "description": "The name for the new playlist",
+                    },
+                    "songs": {
+                        "type": "array",
+                        "description": "A list of songs to add to the playlist",
+                        "items": {
+                            "type": "object",
+                            "properties": {
+                                "title": {"type": "string"},
+                                "artist": {"type": "string"},
+                            },
+                            "required": ["title", "artist"],
+                        },
+                    },
+                },
+                "required": ["playlist_name", "songs"],
+            },
+        ),
+    ),
+]
+
+
+@pytest.mark.parametrize(
+    "_, function_declaration, expected_tool_param",
+    function_declaration_test_cases,
+    ids=[case[0] for case in function_declaration_test_cases],
+)
+async def test_function_declaration_to_tool_param(
+    _, function_declaration, expected_tool_param
+):
+  """Test function_declaration_to_tool_param."""
+  assert (
+      function_declaration_to_tool_param(function_declaration)
+      == expected_tool_param
+  )
+
+
 @pytest.mark.asyncio
 async def test_generate_content_async(
     claude_llm, llm_request, generate_content_response, generate_llm_response