diff --git a/.gitattributes b/.gitattributes
index ca8ff9c..36b9413 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,2 +1,3 @@
 * text=auto eol=lf
+tools/tidy.sh linguist-detectable=false
 .github/.cspell/rust-dependencies.txt linguist-generated
diff --git a/tools/tidy.sh b/tools/tidy.sh
index 54d4122..da034ec 100755
--- a/tools/tidy.sh
+++ b/tools/tidy.sh
@@ -21,9 +21,10 @@ cd -- "$(dirname -- "$0")"/..
 # - clang-format (if C/C++/Protobuf code exists)
 # - parse-dockerfile <https://github.com/taiki-e/parse-dockerfile> (if Dockerfile exists)
 #
-# This script is shared with other repositories, so there may also be
-# checks for files not included in this repository, but they will be
-# skipped if the corresponding files do not exist.
+# This script is shared by projects under github.com/taiki-e, so there may also
+# be checks for files not included in this repository, but they will be skipped
+# if the corresponding files do not exist.
+# It is not intended for manual editing.
 
 retry() {
   for i in {1..10}; do