Fix comment
diff --git a/tools/BUILD b/tools/BUILD
index c70f030..117d343 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -15,5 +15,5 @@
 
 licenses(["notice"])  # Apache 2.0
 
-# This is generated and updated by ./update_piptool.sh
+# This is generated and updated by ./update_tools.sh
 exports_files(["piptool.par"])