diff --git a/src/google/adk/tools/toolbox_tool.py b/src/google/adk/tools/toolbox_tool.py
index 3097d9e..e0a1ed8 100644
--- a/src/google/adk/tools/toolbox_tool.py
+++ b/src/google/adk/tools/toolbox_tool.py
@@ -14,7 +14,6 @@
 
 from typing import Any
 
-from . import _automatic_function_calling_util
 from .langchain_tool import LangchainTool
 
 
@@ -35,12 +34,12 @@ class ToolboxTool:
   def __init__(self, url: str):
     from toolbox_langchain import ToolboxClient
 
-    self.toolbox_client = ToolboxClient(url)
+    self._toolbox_client = ToolboxClient(url)
 
   def get_tool(self, tool_name: str) -> LangchainTool:
-    tool = self.toolbox_client.load_tool(tool_name)
+    tool = self._toolbox_client.load_tool(tool_name)
     return LangchainTool(tool)
 
   def get_toolset(self, toolset_name: str) -> list[LangchainTool]:
-    tools = self.toolbox_client.load_toolset(toolset_name)
+    tools = self._toolbox_client.load_toolset(toolset_name)
     return [LangchainTool(tool) for tool in tools]
diff --git a/src/google/adk/tools/transfer_to_agent_tool.py b/src/google/adk/tools/transfer_to_agent_tool.py
index dea624e..b791a25 100644
--- a/src/google/adk/tools/transfer_to_agent_tool.py
+++ b/src/google/adk/tools/transfer_to_agent_tool.py
@@ -15,7 +15,6 @@
 from .tool_context import ToolContext
 
 
-# TODO: make this internal, since user doesn't need to use this tool directly.
 def transfer_to_agent(agent_name: str, tool_context: ToolContext):
   """Transfer the question to another agent."""
   tool_context.actions.transfer_to_agent = agent_name