The one sentence job is the item I would make mandatory before anything else on this list. If the seller cannot state what the agent does in one sentence, with a clear input and a clear result, every other answer will be vague too.

The messy input demo is the second strongest point. Demos are built on clean examples, while real inboxes and spreadsheets contain duplicates, missing fields and attachments in odd formats. Asking the vendor to run your own worst ten examples live tells you more than any slide.

I would add one question to the failure handling section: what does the agent do when it is unsure, and who sees that case? A good build routes uncertain items to a person with the reason attached, and counts how often that happens. That number is also the most honest measure of whether the agent is improving over time.

The exit path question is a good final filter.