I also found a tool from Texas Instruments, helping to generate composite descriptors as well as corresponding .INF files. Unfortunately, this tool is focused on MSP430, but the generated descriptors are written as C structures, so they may be of any help for comparing with current descriptors for CDC-HID in Espruino.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I also found a tool from Texas Instruments, helping to generate composite descriptors as well as corresponding .INF files. Unfortunately, this tool is focused on MSP430, but the generated descriptors are written as C structures, so they may be of any help for comparing with current descriptors for CDC-HID in Espruino.