long, narrow shape of a tool pocket is what keeps the contents from rattling around. Your leg presses the fabric against the tool, so it rides quietly while you move. A regular cargo pocket flopping open at the top can’t do that with a long object.
This is also why the slot looks odd when empty. It’s cut to hug a shape you aren’t wearing yet.
How the Upside-Down Pocket Keeps a Tool Secure
The mechanics are simple once you see them in action. The sleeve is narrow, so it grips the tool along its length rather than letting it swing. Because the opening faces down, you draw the tool straight out with a downward pull, even while walking.
A top-opening cargo pocket has the opposite problem. Crouch, bend, or scramble over something, and a top opening tips toward the ground. Loose contents can spill. Good cargo pockets fight this
