As the diagram, gives us idea on how people from Stone Age used to craft tools, Two different kinds of tools are shown with various angles, tool A and tool B, both are 1.4 million and 0.8 million years old respectively. Commonality between both the tools are of their similar height, which stands at 5 cm long despite the difference between 6 hundred thousand years.
Moreover, if we notice the front view of the tool made over a million year ago, visible low-effort is shown in comparison to the one which is 0.8 million years old. tool B looking like a round crystal-like stone that has been efficiently carved to get the pointy part on the upper outer edge of it. While the one, on the other hand looks like a stone which could be naturally pointy that had gone through some minor work.
Interestingly, we also have, side and back view of both the tools. Advancement of human intelligence also took a major part into creating sharper object which is immensely evident in the side view of tool A and B, one that developed later has slim sides which is better at performing tasks of cutting objects. Apparently, back view of both the tools maintained a fair similarity, which allowed us to come to a conclusion that grip of tools was not an issue or they might be comfortable to hold.