def METHOD_NAME(agent_method: Callable) -> Callable[..., ContractReturnValue]:
    """
    Marks an agent method as containing contract interactions (transaction or call)
    and validates outbound checksum addresses for EIP-55 compliance.
    If `COLLECT_CONTRACT_API` is True when running tests,
    all marked methods will be collected for automatic mocking
    and integration with pytest fixtures.
    """
    if COLLECT_CONTRACT_API:
        agent_method.contract_api = interface
    agent_method = validate_checksum_address(func=agent_method)
    return agent_method