diff --git a/libs/wingsdk/src/shared-aws/util.ts b/libs/wingsdk/src/shared-aws/util.ts
index a8d3dfe8eab..8c669b357f1 100644
--- a/libs/wingsdk/src/shared-aws/util.ts
+++ b/libs/wingsdk/src/shared-aws/util.ts
@@ -7,6 +7,9 @@ export function isValidArn(arn: string, service: string) {
     return true;
   }
 
+  // ARN format: arn:partition:service:region:account-id:resource-type?:resource
+  // e.g. arn:aws:lambda:us-east-1:111111111111:function:Function-11111111
+  // or,  arn:aws:sqs:us-east-1:111111111111:Queue-11111111
   const parts = arn.split(":");
   if (parts.length < 6 || parts.length > 7) {
     return false;