Didn't expected to have so much fun with this game! I was put off at first because there was a lack of instructions, but I was able to figure the game's mechanics out though the animation feedback. This deserves praise!
As @Humane Tiger already wrote, planning ahead would increase the fun even more by having a Tetris-like preview of the next tool. Another idea would be to kind of 'save' tools for later use in the selection. Dunno. What I want to communicate is that I see potential. Both in the game and in you as a dev. Keep going!