VertexAISearchTool is not accessible

[naitik-parekh]

I have created the following agent hierarchy using ADK 1.13.0.

The code snippets of agents definition are as follows:

agent_2 = Agent()
agent_3 = Agent()
agent_4 = Agent()

agent_1 = Agent(
    sub_agents = [agent_2, agent_3, agent_4]
)

agent_6 = Agent(
    tools = [VertexAiSearchTool()]
)

agent_5 = Agent(
    tools = [AgentTool(agent=agent_6, skip_summarization=True)]
)

agent_7 = Agent(
    tools=[VertexAiSearchTool()]
)

root_agent = Agent(
    sub_agents=[
        agent_1,
        agent_5,
    ],
    tools=[
        AgentTool(agent=agent_7, skip_summarization=True)
    ],
)

The VertexAiSearchTool under agent_6 is not working. The agent_6 replies that tool is not found or not accessible.

I am familiar with the limitation that "Built-in tools cannot be used within a sub-agent". In the agent hierarchy I have created, is the VertexAiSearchTool under agent_6 not working due to this limitation? I have used AgentTool for agent_6 to mitigate the limitation. But is it the case that as agent_5 is a sub-agent, any configuration under it cannot use built-in tools?

[naitik-parekh]

I have initialized VertexAiSearchTool with data_store_id. For this configuration I do not think there is a need to map the data store to a search app. Correct me if I am wrong.

Apparently, after creating a new search app in the AI Applications Console and linking it to the data store used by agent_6's VertexAiSearchTool, the agent has been intermittently retrieving responses from the data store. On several occasions, agent_6 returns an LLM response such as, “The tool I need to use ............ is not working right now".

Is there a need to have the data store connected to any search app for it to be used in VertexAiSearchTool?

When the LLM response says that tool is not working, I do not see any errors/failures in the ADK debug logs. Is this expected behaviour? What can be checked further to find the issue?