I'm still a strictly G-code guy, though this applies to CAD too.

If I have a 0.125" radius end mill (for example), I mic the OD of the tool for cutter diameter (say 0.500 for my example) and touch off on the bottom for tool length. In use, I use a G41.1 or G42.1 with a "D" parameter of "0.500 - (2 * 0.125) + 0.005". I'll use a Z of "0.125 - 0.005" when cutting. That keeps me 0.005" in X/Y and Z off the surface and edge of the part so the cutter doesn't gouge.

Curious if that's how the rest of you define those tools? I could see setting the cutter diameter at the bottom of the tool and doing a "D" parameter of the diameter at the bottom + 0.005" to stay a bit off the work.

Thanks, Bruce