allow custom name/description when VertexAiSearchTool is swapped

src/google/adk/agents/llm_agent.py

@@ -167,17 +167,28 @@ async def _convert_tool_union_to_tools(
   # other tools.
   # TODO: Remove once the workaround is no longer needed.
   if multiple_tools and isinstance(tool_union, VertexAiSearchTool):
-    from ..tools.discovery_engine_search_tool import DiscoveryEngineSearchTool
-
     vais_tool = tool_union
     if vais_tool.bypass_multi_tools_limit:
+      # Imported lazily and only on the bypass path: the Discovery Engine
+      # client is an optional dependency, and agents that leave the flag off
+      # must not be forced to install it.
+      try:
+        from ..tools.discovery_engine_search_tool import DiscoveryEngineSearchTool
+      except ImportError as e:
+        raise ImportError(
+            'bypass_multi_tools_limit=True requires the Discovery Engine'
+            ' client. Install it with `pip install google-adk[gcp]`.'
+        ) from e
+
       return [
           DiscoveryEngineSearchTool(
               data_store_id=vais_tool.data_store_id,
               data_store_specs=vais_tool.data_store_specs,
               search_engine_id=vais_tool.search_engine_id,
               filter=vais_tool.filter,
               max_results=vais_tool.max_results,
+              name=vais_tool._name_override,
+              description=vais_tool._description_override,
           )
       ]
   from ..workflow._base_node import BaseNode

src/google/adk/tools/discovery_engine_search_tool.py

@@ -28,6 +28,7 @@
 import google.auth
 from google.cloud import discoveryengine_v1beta as discoveryengine
 from google.genai import types
+from typing_extensions import override
 
 from ..utils._mtls_utils import get_api_endpoint
 from .function_tool import FunctionTool
@@ -144,6 +145,8 @@ def __init__(
       *,
       search_result_mode: Optional[SearchResultMode] = None,
       location: Optional[str] = None,
+      name: Optional[str] = None,
+      description: Optional[str] = None,
   ):
     """Initializes the DiscoveryEngineSearchTool.
 
@@ -164,8 +167,16 @@ def __init__(
       location: Optional endpoint location override.
         Examples: "global", "us", "eu". If not specified, location is inferred
           from `data_store_id` or `search_engine_id` and defaults to "global".
+        name: Optional override for the tool name advertised to the model.
+        Defaults to the function name, "discovery_engine_search".
+      description: Optional override for the tool description advertised to
+        the model. Defaults to the function docstring.
     """
     super().__init__(self.discovery_engine_search)
+    if name:
+      self.name = name
+    if description:
+      self.description = description
     if (data_store_id is None and search_engine_id is None) or (
         data_store_id is not None and search_engine_id is not None
     ):
@@ -200,6 +211,22 @@ def __init__(
         credentials=credentials, client_options=options
     )
 
+  @override
+  def _get_declaration(self) -> Optional[types.FunctionDeclaration]:
+    # FunctionTool builds the declaration from `self.func`, ignoring
+    # `self.name`. LlmRequest.append_tools advertises `declaration.name` to the
+    # model but keys dispatch on `tool.name`; if the two diverge the model emits
+    # a call that cannot be resolved. Keep them in sync here.
+    #
+    # Safe to mutate: FunctionTool._get_declaration() already returns
+    # `declaration.model_copy(deep=True)`, so the shared
+    # `_build_declaration_cached` lru_cache entry is not touched.
+    declaration = super()._get_declaration()
+    if declaration is not None:
+      declaration.name = self.name
+      declaration.description = self.description
+    return declaration
+
   def discovery_engine_search(
       self,
       query: str,

src/google/adk/tools/vertex_ai_search_tool.py

@@ -71,6 +71,8 @@ def __init__(
       filter: Optional[str] = None,
       max_results: Optional[int] = None,
       bypass_multi_tools_limit: bool = False,
+      name: Optional[str] = None,
+      description: Optional[str] = None,
   ):
     """Initializes the Vertex AI Search tool.
 
@@ -86,6 +88,10 @@ def __init__(
       max_results: The maximum number of results to return.
       bypass_multi_tools_limit: Whether to bypass the multi tools limitation,
         so that the tool can be used with other tools in the same agent.
+      name: Optional tool name. Only takes effect when
+        bypass_multi_tools_limit=True, where it renames the substituted
+        DiscoveryEngineSearchTool. Ignored on the built-in grounding path.
+      description: Optional tool description.
 
     Raises:
       ValueError: If both data_store_id and search_engine_id are not specified
@@ -109,6 +115,8 @@ def __init__(
     self.filter = filter
     self.max_results = max_results
     self.bypass_multi_tools_limit = bypass_multi_tools_limit
+    self._name_override = name
+    self._description_override = description
 
   def _build_vertex_ai_search_config(
       self, readonly_context: ReadonlyContext

tests/unittests/plugins/test_bigquery_agent_analytics_plugin.py

@@ -12200,7 +12200,6 @@ async def test_multiple_plugins_share_background_loop_state_with_equivalent_cred
         creds1
     )
 
-
     plugin1 = bigquery_agent_analytics_plugin.BigQueryAgentAnalyticsPlugin(
         project_id=PROJECT_ID,
         dataset_id=DATASET_ID,