diff --git a/packages/core-types/src/plugin.schema.ts b/packages/core-types/src/plugin.schema.ts
index 15cc2923c..1bdad9558 100644
--- a/packages/core-types/src/plugin.schema.ts
+++ b/packages/core-types/src/plugin.schema.ts
@@ -543,7 +543,7 @@ export const schema = {
             },
             "kid": {
               "type": "string",
-              "description": "Key ID"
+              "description": "Optional. Key ID"
             }
           },
           "required": [