i would recommend this place. It is small but has everything you need. Many places in Sintra are bustly and noisy, but this is calm, private, and quiet. The garden is beautiful. The kitchen is exceptionally well appointed.
There were a couple of issues. Izumi gave us the wrong code for the key lockbox, so we were stuck on the street with our bags. She did not respond to our request for help via the airbnb app. Fortunately, a kind neighbor came to our aid and called her, saving us the expense of an international call, and obtaining the correct code. Izumi did not apologize for this mix-up or mention it at all.
Portugal charges a €1 per person per day tourist tax. Other rentals simply included this in the fee but Izumi told us we needed to pay it, an hour before check-out.