I might be missing something, but my assumption is that provided annotations are expected to be incomplete and some manual tuning might be required.
If that assumption is true, then the most obvious way of modifying annotations is eclipse quick fix function that offers annotating types in libraries that have external annotation files defined.
However, that flow does work properly, as eclipse does something not quite intuitive here. When modifying annotation, eclipse expects selectors to be ordered alphabetically, but that as far as I can see, in this project generator uses logical order instead.
This makes it impossible to, for example, properly annotate instance method String#formatted as it gets "intercepted" by super java/lang/Comparable which causes eclipse to insert duplicate annotation entry instead of replacing the one that is located somewhere below.