Speaking of tools the theory (with regard to muslim versus hindu tools) is that circumcision cause the tip of the tool to remain uncovered and lifelong rubbing against chuddie or inside of pant (or pyjama) slowly cause the tip of the tool to become less sensitive. This means that muslim tool requires a lot more repetitive usage before it can discharge vis a vis hindu tool.
But my girlfriend once told me that girls dont like this as a rule of thumb because after a while it ceases to cause excitation and only leads to soreness. And no, the length being unimportant is a myth. A tool that is long enough for its tip to reach and stretch the cervix is preferred. Again it is a delicate balance. Too long tool causes pain. Similarly girth of tool is also critical to activate peripheral stretch receptors. But too broad tool would cause pain and sometimes tears as well.
Hope this explains the myths surrounding tools. This is nothing theoretical. only purely practical based on personal experience and what I have learned along the way.
@mujhaidind hope it helps.