A holiday let is judged on its first impression. A long-stay home is judged on its fortieth week. The questions change accordingly: how reliable is the internet, how is the house in the monsoon, what happens when something breaks.
Ask to see the inventory and agree in writing what is furnished and what is not. Ask who handles maintenance, how quickly, and whether housekeeping is included or arranged separately.
Think about the term. Many owners prefer a minimum of six or twelve months; in return you should expect a clear agreement on notice periods, deposits and what counts as fair wear.
Finally, visit the neighbourhood on a weekday. A village that is lively in season can be very quiet, or very different, in the months between.