Oh I already found a bunch of .tool files, but they are not some kind of easy-to-decipher and/or modify text format, like say a post-processor usually is for some CAM software. They are some kind of special format for which a specification sheet might not have been released to the public yet. You could shoot an email off to Vectric though asking if they have a file format spec for .tool files though.
Viewing post in Tool feature suggestions
Interesting. I am curious as to whether or not they are intentionally keeping it a secret, as a proprietary format, like some software companies do with their unique file types. That's hard to believe though with other programs also supporting the format, but there could be a monetary compensation aspect involved there. I could possibly reverse engineer the format if I were seriously determined to but I am inclined to think that the payoff would not justify the effort - especially when there are much more valuable features and functionality I could be hacking away at with my time. I'll do some more rigorous Googling after the v1.34a build goes out and see what I can come up with. I can't be the only developer interested in using an already existing tool definition format, someone might have already done the hard part of deciphering it. There also might just be an official spec explaining the layout of the parameters in the .tool file that is just harder to dig up because 'tool' is a pretty common word in search results.