The IRR & Payback Calculator

Calculate the return metrics for this project and tell me what they do and
don't reveal.

Upfront investment: [AMOUNT]
Cash flows by year: [LIST]
My hurdle rate: [RATE]

Provide:
1. Internal rate of return (IRR) and how it compares to my hurdle
2. Simple and discounted payback period
3. NPV alongside, so I can see where IRR can mislead
4. Whether IRR is trustworthy here (irregular or sign-changing cash
   flows can break it)
5. A recommendation using the metrics together, not just one

Explain in a line why NPV usually wins the argument when IRR and NPV
disagree.