The baby gate you choose for the top of the stairs should be hardware mounted. This means that you will have to screw into your wall our banister, but the end result is a much safer baby gate. Depending on the model, can be angled.
In most cases, there are clamps that attach directly to your banister allowing you to install the gate without drilling onto your banister. But this depends on the size of your post. (Installation Kit).
The small holes on the wall are easily fixed with plaster and paint. This is a small disadvantage compared to the safety benefits that this model of baby door provides.
Compared to a pressure mounted gate, this kind of gate does not have a threshold to step over. There are no risks of tripping or hurting our toes. The whole gate swings open, not just a passage door, allowing to use almost the entire space in a walkway.