chore: allow "from google.adk.tools import AgentTool"

PiperOrigin-RevId: 784386985

Author: wuliang229

src/google/adk/tools/__init__.py

@@ -14,6 +14,7 @@
 
 
 from ..auth.auth_tool import AuthToolArguments
+from .agent_tool import AgentTool
 from .apihub_tool.apihub_toolset import APIHubToolset
 from .base_tool import BaseTool
 from .example_tool import ExampleTool
@@ -31,6 +32,7 @@
 from .vertex_ai_search_tool import VertexAiSearchTool
 
 __all__ = [
+    'AgentTool',
     'APIHubToolset',
     'AuthToolArguments',
     'BaseTool',

src/google/adk/tools/agent_tool.py

@@ -23,7 +23,6 @@
 
 from . import _automatic_function_calling_util
 from ..memory.in_memory_memory_service import InMemoryMemoryService
-from ..runners import Runner
 from ..sessions.in_memory_session_service import InMemorySessionService
 from ._forwarding_artifact_service import ForwardingArtifactService
 from .base_tool import BaseTool
@@ -103,6 +102,7 @@ async def run_async(
       tool_context: ToolContext,
   ) -> Any:
     from ..agents.llm_agent import LlmAgent
+    from ..runners import Runner
 
     if self.skip_summarization:
       tool_context.actions.skip_summarization = True