Mention something like
   An exit status of zero indicates success, and a nonzero value
   indicates failure.
Else one cannot tell if e.g.,

# alsactl --debug restore; echo $?
alsa-lib parser.c:2372:(load_toplevel_config) Unable to find the top-level configuration file '/usr/share/alsa/ucm2/ucm.conf'.
alsa-lib main.c:1405:(snd_use_case_mgr_open) error: failed to import hw:0 use case configuration -2
alsactl: set_controls:1493: device='hw:0', doit=0
alsactl: set_controls:1505: card-info-id: 'PCH'
alsactl: set_controls:1531: maxnumid=29
alsactl: set_controls:1549: result code: 0
alsactl: set_controls:1493: device='hw:0', doit=1
alsactl: set_controls:1505: card-info-id: 'PCH'
alsactl: set_controls:1531: maxnumid=29
alsactl: set_controls:1549: result code: 0
0

worked or not.