diff --git a/messages/permset.assign.json b/messages/permset.assign.json
index 6788e733..0d93f553 100644
--- a/messages/permset.assign.json
+++ b/messages/permset.assign.json
@@ -1,5 +1,5 @@
 {
-  "description": "assign a permission set to one or more users of an org",
+  "description": "assign a permission set to one or more users of an org\nTo specify an alias for the -u or -o parameter, use the username alias you set with the \"alias:set\" CLI command, not the User.Alias value of the org user.",
   "examples": [
     "sfdx force:user:permset:assign -n DreamHouse",
     "sfdx force:user:permset:assign -n DreamHouse -u me@my.org",