diff --git a/discovery/servicedirectory-v1.json b/discovery/servicedirectory-v1.json
index 7452bf4481..4deb5db90c 100644
--- a/discovery/servicedirectory-v1.json
+++ b/discovery/servicedirectory-v1.json
@@ -883,7 +883,7 @@
       }
     }
   },
-  "revision": "20231217",
+  "revision": "20240121",
   "rootUrl": "https://servicedirectory.googleapis.com/",
   "schemas": {
     "Binding": {
@@ -902,7 +902,7 @@
           "type": "array"
         },
         "role": {
-          "description": "Role that is assigned to the list of `members`, or principals. For example, `roles/viewer`, `roles/editor`, or `roles/owner`.",
+          "description": "Role that is assigned to the list of `members`, or principals. For example, `roles/viewer`, `roles/editor`, or `roles/owner`. For an overview of the IAM roles and permissions, see the [IAM documentation](https://cloud.google.com/iam/docs/roles-overview). For a list of the available pre-defined roles, see [here](https://cloud.google.com/iam/docs/understanding-roles).",
           "type": "string"
         }
       },
diff --git a/discovery/servicedirectory-v1beta1.json b/discovery/servicedirectory-v1beta1.json
index 99b25e1c3e..932dfa537f 100644
--- a/discovery/servicedirectory-v1beta1.json
+++ b/discovery/servicedirectory-v1beta1.json
@@ -971,7 +971,7 @@
       }
     }
   },
-  "revision": "20231217",
+  "revision": "20240121",
   "rootUrl": "https://servicedirectory.googleapis.com/",
   "schemas": {
     "Binding": {
@@ -990,7 +990,7 @@
           "type": "array"
         },
         "role": {
-          "description": "Role that is assigned to the list of `members`, or principals. For example, `roles/viewer`, `roles/editor`, or `roles/owner`.",
+          "description": "Role that is assigned to the list of `members`, or principals. For example, `roles/viewer`, `roles/editor`, or `roles/owner`. For an overview of the IAM roles and permissions, see the [IAM documentation](https://cloud.google.com/iam/docs/roles-overview). For a list of the available pre-defined roles, see [here](https://cloud.google.com/iam/docs/understanding-roles).",
           "type": "string"
         }
       },
diff --git a/src/apis/servicedirectory/v1.ts b/src/apis/servicedirectory/v1.ts
index 7eab5e9d4e..6276e020e2 100644
--- a/src/apis/servicedirectory/v1.ts
+++ b/src/apis/servicedirectory/v1.ts
@@ -137,7 +137,7 @@ export namespace servicedirectory_v1 {
      */
     members?: string[] | null;
     /**
-     * Role that is assigned to the list of `members`, or principals. For example, `roles/viewer`, `roles/editor`, or `roles/owner`.
+     * Role that is assigned to the list of `members`, or principals. For example, `roles/viewer`, `roles/editor`, or `roles/owner`. For an overview of the IAM roles and permissions, see the [IAM documentation](https://cloud.google.com/iam/docs/roles-overview). For a list of the available pre-defined roles, see [here](https://cloud.google.com/iam/docs/understanding-roles).
      */
     role?: string | null;
   }
diff --git a/src/apis/servicedirectory/v1beta1.ts b/src/apis/servicedirectory/v1beta1.ts
index 4cf91583d5..e0360960d4 100644
--- a/src/apis/servicedirectory/v1beta1.ts
+++ b/src/apis/servicedirectory/v1beta1.ts
@@ -137,7 +137,7 @@ export namespace servicedirectory_v1beta1 {
      */
     members?: string[] | null;
     /**
-     * Role that is assigned to the list of `members`, or principals. For example, `roles/viewer`, `roles/editor`, or `roles/owner`.
+     * Role that is assigned to the list of `members`, or principals. For example, `roles/viewer`, `roles/editor`, or `roles/owner`. For an overview of the IAM roles and permissions, see the [IAM documentation](https://cloud.google.com/iam/docs/roles-overview). For a list of the available pre-defined roles, see [here](https://cloud.google.com/iam/docs/understanding-roles).
      */
     role?: string | null;
   }