def __getitem__(self, index: int) -> Tool:
    """Get a tool by index across all toolsets."""
    # Leverage iteration instead of manual index tracking
    for i, tool in enumerate(self):
        if i == index:
            return tool
    raise IndexError("ToolsetWrapper index out of range")

from haystack.tools import Toolset, create_tool_from_function


def addition_tool(a: int, b: int) -> int:
    return a + b


def multiplication_tool(a: int, b: int) -> int:
    return a * b


add_tool = create_tool_from_function(function=addition_tool, name="addition_tool", description="adds two ints")
mult_tool = create_tool_from_function(function=multiplication_tool, name="multiplication_tool", description="multiplies two ints")

combined = Toolset([add_tool]) + Toolset([mult_tool])  # -> _ToolsetWrapper
print(combined[0].name)   # "addition_tool" - fine
print(combined[1].name)   # "multiplication_tool" - fine
print(combined[-1].name)  # IndexError: ToolsetWrapper index out of range

# For comparison, a plain Toolset supports this fine:
print(Toolset([add_tool, mult_tool])[-1].name)  # "multiplication_tool"