This allows the description of the commands to display when listing the commands in bedrock by tab-completing. This is currently only available on Sponge and Bukkit versions as there is no support in BungeeCord and Velocity to get these values. This data is also not sent in any packet, so we cannot retrieve that from standalone either.
The normal identity UUID caused problems and caused the bedrock client to crash when using Floodgate. This was likely because on bedrock edition, it's a version 3 UUID opposed to java edition which uses version 4.