Suppose you want to dig some insects out of a tree trunk. Your fingers are too short to reach the bugs. What should you do? You could make a tool. You could find a stick and sharpen it to a point. You could use the point to spear the insects.
This is a good idea, but someone else thought of it first. Apes use sharp sticks to dig out insects. Apes are so smart that they have learned to make simple tools.