It really helps to read both A Pattern Language and The Timeless Way of Building together, so you get a complete picture of Alexander's thoughts.

OK. It doesn’t really go to your original post, but I often also point people to The Design of Everyday Things, Donald Norman, 1988, https://en.m.wikipedia.org/wiki/The_Design_of_Everyday_Thing...

Basic insight into the question of: “What makes a good tool?” Maybe for your purposes, the angle is: “When is a simplified tool more useful than a complex one?” Or: “How can I add complexity to a tool while preserving its usefulness?”