What are these two things for? disallow_transfer_to_parent , disallow_transfer_to_peers

[xuanyang15]

We need simple examples to illustrate these two things.

[xuanyang15]

Response from ADK Answering Agent

TLDR: disallow_transfer_to_parent and disallow_transfer_to_peers are boolean flags on an agent that control whether it can delegate tasks to its parent agent or to sibling agents, respectively. [2, 5] By default, these are both False, meaning that an agent can transfer tasks to its parent and peers. [4]

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In the Google ADK, agents can be structured in a hierarchy, with parent agents and sub-agents. The AutoFlow feature allows for "agent transfer," which is the delegation of a task from one agent to another. [1] This is particularly useful in multi-agent systems where a coordinator agent might route tasks to specialized sub-agents. [9]

The disallow_transfer_to_parent and disallow_transfer_to_peers properties give you fine-grained control over this transfer mechanism.

disallow_transfer_to_parent

When this property is set to True on a sub-agent, it is not allowed to transfer a task up to its parent agent. [2] This is useful when you want to ensure that a sub-agent either handles a task itself or delegates it to one of its own sub-agents, but never back to the agent that invoked it.

disallow_transfer_to_peers

When this property is set to True on a sub-agent, it is not allowed to transfer a task to its "peer" agents (i.e., other sub-agents of the same parent). [1, 2] This can be used to enforce a strict chain of command and prevent "sideways" delegation.

Example

Here is a conceptual example of how you might use these properties:

from google.adk.agents import LlmAgent

# A specialized agent for handling billing inquiries.
# We don't want it to delegate tasks to anyone else, so we disallow
# transfers to its parent (the coordinator) and its peers.
billing_agent = LlmAgent(
    name="Billing",
    description="Handles billing inquiries.",
    disallow_transfer_to_parent=True,
    disallow_transfer_to_peers=True,
)

# A specialized agent for providing technical support.
# It can escalate issues to the coordinator, but shouldn't pass tasks
# to the billing agent.
support_agent = LlmAgent(
    name="Support",
    description="Handles technical support requests.",
    disallow_transfer_to_peers=True,
)

# The main coordinator agent.
# It has sub-agents for billing and support.
coordinator = LlmAgent(
    name="HelpDeskCoordinator",
    model="gemini-1.5-flash",
    instruction="Route user requests to the appropriate sub-agent.",
    description="Main help desk router.",
    sub_agents=[billing_agent, support_agent],
)

In this example:

• If a task is transferred to billing_agent, it must handle it itself. It cannot transfer the task to coordinator or support_agent.
• If a task is transferred to support_agent, it can handle it or transfer it to coordinator, but it cannot transfer it to billing_agent.
• The coordinator can transfer tasks to billing_agent and support_agent.

When an agent has disallow_transfer_to_parent=True, disallow_transfer_to_peers=True, and no sub-agents of its own, it uses a SingleFlow instead of an AutoFlow, effectively making it a standalone agent that cannot delegate. [5]

[1] https://github.com/google/adk-python/blob/main/src/google/adk/flows/llm_flows/auto_flow.py
[2] https://github.com/google/adk-python/blob/main/src/google/adk/flows/llm_flows/agent_transfer.py
[4] https://github.com/google/adk-python/blob/main/tests/unittests/agents/test_llm_agent_fields.py
[5] https://github.com/google/adk-python/blob/main/src/google/adk/agents/llm_agent.py
[9] https://github.com/google/adk-docs/blob/main/docs/agents/multi-agents.md