preload_memory_tool not found error

[sshv84]

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**Describe the Bug: Installed 1.23.0 adk version and **
A clear and concise description of what the bug is.

Steps to Reproduce:
Please provide a numbered list of steps to reproduce the behavior:

1. Install 'google-adk==1.23.0'

2. Run 'from google.adk.tools.load_memory_tool import load_memory_tool
   from google.adk.tools.preload_memory_tool import preload_memory_tool
   root_agent = LlmAgent(
   name="kroger_agent",
   description="A Kroger Shopping Assistant that helps find stores and search for products",
   model=MODEL,
   sub_agents=[products_agent, locations_agent],
   instruction="""You are a Shopping Assistant with access to:
   (1) API tools, and
   (2) the user's Memory Bank (via preload_memory).

   """,
   tools=[
   FunctionTool(func=save_user_state),
   FunctionTool(func=update_user_state),
   FunctionTool(func=get_user_preferences),
   preload_memory_tool
   ]'

3. Open 'Logs'

4. Provide error or stacktrace. 2026-01-28 19:07:14.503 EST
   Traceback (most recent call last):
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/cli/adk_web_server.py", line 1534, in event_generator
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/runners.py", line 562, in run_async
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/runners.py", line 550, in _run_with_trace
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/runners.py", line 779, in _exec_with_plugin
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/runners.py", line 539, in execute
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/agents/base_agent.py", line 294, in run_async
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/agents/llm_agent.py", line 468, in _run_async_impl
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/base_llm_flow.py", line 382, in run_async
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/base_llm_flow.py", line 469, in _run_one_step_async
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/base_llm_flow.py", line 582, in _postprocess_async
   async for event in agen:
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/base_llm_flow.py", line 700, in _postprocess_handle_function_calls_async
   if function_response_event := await functions.handle_function_calls_async(
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/functions.py", line 199, in handle_function_calls_async
   return await handle_function_call_list_async(
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/functions.py", line 245, in handle_function_call_list_async
   function_response_events = await asyncio.gather(*tasks)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/functions.py", line 339, in _execute_single_function_call_async
   raise tool_error
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/functions.py", line 325, in _execute_single_function_call_async
   tool = _get_tool(function_call, tools_dict)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   File "/home/myuser/.local/lib/python3.11/site-packages/google/adk/flows/llm_flows/functions.py", line 730, in _get_tool
   raise ValueError(error_msg)
   ValueError: Tool 'preload_memory_tool' not found.

Expected Behavior: preload_memory_tool should be able to work properly
A clear and concise description of what you expected to happen.

Observed Behavior:
What actually happened? Include error messages or crash stack traces here.

Environment Details:

• ADK Library Version (pip show google-adk):
• Desktop OS:** [e.g., macOS, Linux, Windows]
• Python Version (python -V):

Model Information:

• Are you using LiteLLM: Yes/No No
• Which model is being used: (e.g., gemini-2.5-pro) gemini-2.0-flash

---

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Regression:
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