Custom tools error about is_single_input

[MightyMoud]

Hi guys,

After last upgrade I'm getting this error every time I try to add a custom tool.

llm_math_chain = LLMMathChain(llm=llm, verbose=True)

tools = [
    Tool.from_function(
        func=llm_math_chain.run,
        name="Calculator",
        description="Useful when doing calculations",
    )
]

agent = initialize_agent(
    llm,
    tools,
    agent=AgentType.ZERO_SHOT_REACT_DESCRIPTION,
    verbose=True,
)
agent.run("What is 3 time 4?")

The error i'm getting is:
AttributeError: 'tuple' object has no attribute 'is_single_input'

Am I doing something wrong here?