According to the author's side account b_cusk on twitter/x (g_jyeo is the main), Andrew is...

According to the author's side account b_cusk on twitter/x (g_jyeo is the main), Andrew is actually bad at using tools. They wanted to show that even though Andrew is someone who excels at everything, he still grew up without learning some important life aspects. However once Luke taught him how to handle tools, Andrew was able to drill the nails into the board beautifully and neatly. They said they wanted to leave the interpretation of the story to the readers since there is not much room for interpretation in the story itself. However, they believed a little explanation was necessary for this chapter. It makes sense because we are all seeing this event from the perspective of Luke's friend who knows nothing about everything going on between Luke and Andrew.