I’ve created a new tool called gdtool which takes a Web specification and outputs the GroupData.json-formatted JSON that lists the tool’s interfaces, dictionaries, and so forth. It’s a bit of a skeleton still since it doesn’t yet know how to fill out the methods and properties sections, or events, but those are things it could be updated to handle.
It can be found here: https://github.com/a2sheppy/gdtool
I’m likely going to tackle adding code to pull event information next, because it should not be too hard; I can find the table that lists them fairly easily, near the end. And methods and properties are going to be those items which are included in partial interfaces, so I can get those too.