Hello so I’m making a homebrew class for the artificer and one of the features gives you proficiency with woodcarvers tools or another tool of your choice if you already have proficiency with them is there a way I can make it so it detects if you already have proficiency kinda like with backgrounds if you already have a proficiency they give you can choose another one.

You can’t really, the way they do it is locked behind a secret in a dropdown we can’t access. The best you can do is give them the option to choose any set of artisan’s tools and trust them to pick the right one.