To bury posts you want straight narrow holes in the ground. Traditional post hole diggers tend to flare the hole at the top as the hole deepens because the handles must swing out further. This clever improved design from Fiskars crosses the handles so they don’t swing out as far in the hole, yet they still bite as the hole gets deeper. The narrower the hole, the less dirt to remove, the less work. I found I could get a tight cylindrical hole almost one foot deeper with this tool. Also, this design prevents that dreaded knuckle-banger when the handles crash into each other on the closing stroke, which alone makes it worth using.
A cool tool is anything useful that is superior to comparable items. If you think this tool is inferior suggest a better one. You are welcome to insult a tool, but comments containing insults to individual people will be deleted. Corrections of fact are always welcomed, if stated politely. Recommendations of better tools are dearly wanted and may be elevated to the front page.