diff --git a/tools/test_apps/protocols/mqtt/build_test/README.md b/tools/test_apps/protocols/mqtt/build_test/README.md
index 70fb332..6fa99ab 100644
--- a/tools/test_apps/protocols/mqtt/build_test/README.md
+++ b/tools/test_apps/protocols/mqtt/build_test/README.md
@@ -1,3 +1,8 @@
+| Supported Targets | ESP32 | ESP32-S2 | ESP32-S3 | ESP32-C3 |
+| ----------------- | ----- | -------- | -------- | -------- |
+
+Not support on ESP8684 yet, waiting esp_wifi supported. TODO: IDF-3905
+
 # Build only test for C++
 
 This test app ensures that calling all mqtt-client API could be called from C++