Where can I get more information on the sm tool (command) used in the Terminal I have seen the sm tool used a few places for example here.

The way I understand it, it is a storage management tool but I haven't been successful in finding any more info about it.

Where can I find more information on this tool?
The sm tool is not an Android tool, it's a linux shell command.  Android devices have some shell commands located in /system/bin - the variety of these usually vary by version, OEM, and platform.

You can issue this adb command to see what tools are available:

adb shell ls system/bin


You can ask for help on each tool - for example, with sm:

$ adb shell sm -help
usage: sm list-disks [adoptable]
       sm list-volumes [public|private|emulated|all]
       sm has-adoptable
       sm get-primary-storage-uuid
       sm set-force-adoptable [true|false]
       sm set-virtual-disk [true|false]

       sm partition DISK [public|private|mixed] [ratio]
       sm mount VOLUME
       sm unmount VOLUME
       sm format VOLUME
       sm benchmark VOLUME
       sm fstrim

       sm forget [UUID|all]

       sm set-emulate-fbe [true|false]