The desk was especially trying. The bookshelf took a calm understanding of how to work with gravity and a bit of candle wax on the screws to help them go in easier. The hex-key comes included and the other tools needed are a hammer or mallet and an optional bit of candlewax. Got it together by myself in under half an hour.
https://www.amazon.com/Winsome-Wood-82427-Mission-Shelving/dp/B000NPONBO