diff --git a/README.md b/README.md
index 9d95c82..762327a 100644
--- a/README.md
+++ b/README.md
@@ -107,6 +107,8 @@ The following payload will succeed.
 client-payload: '{"github": ${{ toJson(github) }}}'
 ```
 
+Additionally, there is a limitation on the total data size of the `client-payload`. A very large payload may result in a `client_payload is too large` error.
+
 ## License
 
 [MIT](LICENSE)