Describe the lockbox or keypad by POSITION, not colour — "on the right-hand post as you face the front door". Guests arriving after dark can't use colour.

Include any warning about the driveway — steepness, sharp turns, low-clearance cars. Guests who are told in advance don't complain; guests who discover it do.

Say which thermostat or mini-split controls which room. "No heat in the downstairs bedroom" is usually a unit the guest didn't know existed.

If the tank supports fewer showers than the house sleeps, say so and give the refill time. This one line prevents a very common complaint.

If it's heated, give the temperature and how long it takes to warm up. If guests can adjust it, tell them how — most complaints about a "cold pool" are guests who were never told.

Quirks only — e.g. whether the coffee maker takes pods or grounds. Small ambiguities generate real complaints.