diff --git a/tools/.eslintrc.yaml b/tools/.eslintrc.yaml
new file mode 100644
index 00000000000000..f8b7cc4e41a747
--- /dev/null
+++ b/tools/.eslintrc.yaml
@@ -0,0 +1,4 @@
+rules:
+  # Variables
+  # http://eslint.org/docs/rules/#variables
+  no-unused-vars: [error, { args: 'after-used' }]
diff --git a/tools/doc/html.js b/tools/doc/html.js
index 5534dd03b7441a..e25192599593f3 100644
--- a/tools/doc/html.js
+++ b/tools/doc/html.js
@@ -224,7 +224,7 @@ function altDocs(filename) {
   const host = 'https://nodejs.org';
   const href = (v) => `${host}/docs/latest-v${v.num}/api/${filename}.html`;
 
-  function li(v, i) {
+  function li(v) {
     let html = `<li><a href="${href(v)}">${v.num}`;
 
     if (v.lts)
diff --git a/tools/eslint-rules/crypto-check.js b/tools/eslint-rules/crypto-check.js
index b1b2a03f50e3b6..9d24d3355dce7f 100644
--- a/tools/eslint-rules/crypto-check.js
+++ b/tools/eslint-rules/crypto-check.js
@@ -54,7 +54,7 @@ module.exports = function(context) {
     }
   }
 
-  function reportIfMissingCheck(node) {
+  function reportIfMissingCheck() {
     if (hasSkipCall) {
       return;
     }