This apparently got updated

plugins/labels.py

@@ -1,6 +1,6 @@
 from beets import ui
 from beets.ui import Subcommand, print_
-from beets.ui.commands import print_and_modify
+from beets.ui.commands.modify import print_and_modify
 from beets.dbcore import FieldQuery
 from beets.dbcore.query import SlowFieldSort
 
@@ -65,11 +65,14 @@ action_map = {
 }
 
 def modify_labels(lib, opts, args):
+    if not args:
+        labels_command.parser.print_usage()
+        return
+
     action = args[0]
 
     if action not in action_map:
-        print_("%s is not a valid action. " % action)
-        print_("Valid actions are: add, remove, removeall, show, transfer, edit")
+        print_("%s is not a valid action. Run 'beet labels --help' for usage." % action)
         return
 
     actnum = action_map[action]
@@ -297,7 +300,20 @@ def edit_labels(lib, opts, args):
 
     print_(f"Updated {len(changes)} item(s).")
 
-labels_command = Subcommand('labels', help='Add or remove labels')
+labels_command = Subcommand(
+    'labels',
+    help='Add, remove, or inspect labels on library items'
+)
+labels_command.parser.usage = """%prog <action> [args] [query]
+
+Actions:
+  add <label>[:<cost>] [query]  Add a label (optionally with a cost value)
+  remove <label> [query]        Remove a label from items
+  removeall [query]             Remove all labels from items
+  show [query]                  Display labels on items
+  transfer <src-query> <dst-query>
+                                Copy labels from one item to another
+  edit [query]                  Open items' labels in a text editor"""
 labels_command.func = modify_labels
 
 class HasLabelQuery(FieldQuery):