There is no "document with documentation", be it comments or as companion side resource with an obvious cross-reference.

There was no mention here on rushing to anything. Verbosity is not always bringing actual non-duplicating information. And even when the explicit way is taken, it can be put aside from human main analysis observation point. Actually even Typscript allow to organize type information by using .d.ts files for declaration files that contain only type information, while implementation files use the .ts extension.

Then there is the tradeoff between grepable explicit type and spare implementation with as much type inference as possible.