diff --git a/tools/README b/tools/README
index 3a0818cd..fffe7191 100644
--- a/tools/README
+++ b/tools/README
@@ -1,6 +1,11 @@
 README
 
-The SDK uses 'kconfig', 'idf_monitor.py' of esp-idf and information of esp-idf is following:
+Information of 'idf_monitor.py' is following:
 
 URL: https://github.com/espressif/esp-idf
 tag: v3.1-dev
+
+Information of 'cmake', 'kconfig', 'kconfig_new' and 'idf.py' is following:
+
+commit: 48c3ad37
+