The short descriptions describe the data each info retrieves. The info
itself does not 'get' the data.
This simplifies and shortens the descriptions and make them more
consistent.
Closes#19406
Expand a little.
- mention the type name of the return code
- avoid stating which exact return codes that might be returned, as that
varies over time, builds and conditions
- avoid stating some always return OK
- refer to the manpage documenting all the return codes
Closes#15900
