diff --git a/specification/communication/data-plane/CallAutomation/preview/2023-06-15-preview/communicationservicescallautomation.json b/specification/communication/data-plane/CallAutomation/preview/2023-06-15-preview/communicationservicescallautomation.json
index 8d6e5b0ad3be..47c5efce39c6 100644
--- a/specification/communication/data-plane/CallAutomation/preview/2023-06-15-preview/communicationservicescallautomation.json
+++ b/specification/communication/data-plane/CallAutomation/preview/2023-06-15-preview/communicationservicescallautomation.json
@@ -2758,7 +2758,7 @@
   "securityDefinitions": {
     "Authorization": {
       "type": "apiKey",
-      "description": "An Azure Communication Services user access token.",
+      "description": "An authentication string containing a signature generated using HMAC-SHA256 scheme.",
       "name": "Authorization",
       "in": "header"
     }
diff --git a/specification/communication/data-plane/CallAutomation/stable/2023-03-06/communicationservicescallautomation.json b/specification/communication/data-plane/CallAutomation/stable/2023-03-06/communicationservicescallautomation.json
index a0d2c888957f..1f9138eebf82 100644
--- a/specification/communication/data-plane/CallAutomation/stable/2023-03-06/communicationservicescallautomation.json
+++ b/specification/communication/data-plane/CallAutomation/stable/2023-03-06/communicationservicescallautomation.json
@@ -2149,7 +2149,7 @@
   "securityDefinitions": {
     "Authorization": {
       "type": "apiKey",
-      "description": "An Azure Communication Services user access token.",
+      "description": "An authentication string containing a signature generated using HMAC-SHA256 scheme.",
       "name": "Authorization",
       "in": "header"
     }