What are "Tool Marks"?

[Morsecode]

I see this on PCGS slabs (early dollars & half dollars, mostly) but I'm not sure what they are, or where. Do they mean adjustments as made by mint employees, or from coin enhancements some time later?

Tried search engine but didn't come up with much.

[coppernickel]

In the early days, when gold and silver were money, blanks were made a little over weight then filed to be the correct weight.

The mint employees did file the blanks before the coins were struck. It leaves a very distinct "tool mark" on the finished coins.

It is a different mark than being filed after minting.

[Morsecode]

So I asume that meant filing the edge of a coin, rather than gouging out from the fields.

I guess I was confused because the way PCGS put it on the slab it made it sound like something undesireable about the coin that impacted it's value, like "Improperly Cleaned", which I see a lot. Tooling is a neat bit of history...why wouldn't you want it?

[coppernickel]

From the Redbook explanation, across the face would not surprise me. This would be before the striking. I have never seen any of them.