VertexAiSearchTool() call not visible in exectution

[petrupetru]

I have one LlmAgent() with multiple VertexAiSearchTool() tools. The problem is that nowhere in akd web, or even in the response events i can find the tools call. In adk web it looks like i have only one tool named "vertex_ai_search", and tool callbacks are not triggered by the seach. The agent works, I get grounded responses, but i want to see somewhere the execution and also give names to my search tools so i can reference them in the prompt.

In adk web UI i only get 1 event per query, so it shows only one tool and no calls to it

Agent:

root_agent = LlmAgent( name="menu_agent", model=MODEL, description=( "This agent ..." ), instruction=prompt, output_key="menu_output", tools=[ 1_tool, 2_tool, 3_tool, 4_tool, ], after_tool_callback=simple_after_tool_modifier, )

Tool example:

1_tool= VertexAiSearchTool( search_engine_id=f"projects/{PROJECT_ID}/locations/{LOCATION}/collections/default_collection/engines/{ENGINE_ID}" )

Tool callback:

def simple_after_tool_modifier( tool: BaseTool, args: Dict[str, Any], tool_context: ToolContext, tool_response: Dict ) -> Optional[Dict]: """Inspects/modifies the tool result after execution.""" agent_name = tool_context.agent_name tool_name = tool.name print(f"[Callback] After tool call for tool '{tool_name}' in agent '{agent_name}'") print(f"[Callback] Args used: {args}") print(f"[Callback] Original tool_response: {tool_response}") return None

[adk-bot]

Response from ADK Answering Agent (experimental, answer may be inaccurate)

TLDR: The behavior you're observing with VertexAiSearchTool seems to be a combination of default behavior and a potential issue with how the tool calls are displayed. The tool name is not directly customizable, and the lack of visibility in the UI might be due to the specific way this built-in tool is implemented. Your after_tool_callback should work, but it's worth checking for plugin interference.

---

Hello @petrupetru,

Thank you for your detailed question. Here is some information based on the ADK documentation that might help clarify the situation.

Naming of VertexAiSearchTool

From the documentation and the source code, it appears that the VertexAiSearchTool does not have a user-configurable name parameter in its constructor [1]. The name "vertex_ai_search" seems to be the default and is not intended to be changed. This is likely because it's a built-in tool with a specific purpose for grounding.

after_tool_callback Not Triggering

The after_tool_callback you've defined is indeed the correct way to inspect the results of a tool call within an LlmAgent [2]. However, the order of callback execution could be a factor here. If you have any plugins enabled, their after_tool_callbacks will run before the one you've defined for the agent. If a plugin's callback returns a non-None value, it might prevent the agent-level callback from being executed [3]. You can find more details on the callback execution flow in the documentation [4].

UI Visibility of Tool Calls

The ADK web UI is designed to provide detailed logs of agent execution. The "Events" tab should show the sequence of tool calls and responses, and the "Trace" tab provides an even more granular view of the execution [5].

Given that you are not seeing the individual tool calls, here are a couple of suggestions:

1. Check the "Trace" Tab: The "Trace" tab often contains more detailed logging information than the "Events" tab. It might provide more insight into the internal workings of the agent and why the tool calls are not being displayed as you expect.
2. Update to the Latest Version: The ADK is under active development. It's possible that this is a known issue that has been addressed in a more recent version. Please check the CHANGELOG and consider updating to the latest version of the google-adk package.
3. Isolate the Issue: Try creating a very simple agent with just one VertexAiSearchTool and your callback. This can help determine if the issue is with the tool itself or an interaction with the other tools in your more complex agent.

I hope this information is helpful. While it doesn't provide a direct solution for renaming the tools, it might help you debug the callback and visibility issues.

---

[1] https://github.com/google/adk-python/blob/main/src/google/adk/tools/vertex_ai_search_tool.py
[2] https://google.github.io/adk-docs/agents/llm-agents/
[3] https://google.github.io/adk-docs/plugins/
[4] https://github.com/google/adk-python/blob/main/src/google/adk/flows/llm_flows/functions.py
[5] https://google.github.io/adk-docs/get-started/quickstart/

[petrupetru]

1. There is nothing about the tool calls in the trace tab
2. I did update an nothing changed
3. i did the simple agent and it it the same thing

Should i consider a workaround like creating a custom tool for the search? would this affect the performance?

[yrangana]

There is a bug that neither before_tool_callback or after_tool_callback is triggered when VertexAiSearchTool is used as a tools for Agent. #1121