diff --git a/Cargo.toml b/Cargo.toml
index ac621fe..6004a36 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,3 +9,6 @@ license = "MIT"
 [lints.clippy]
 all = { level = "warn", priority = -1 }
 pedantic = { level = "warn", priority = -1 }
+allow_attributes_without_reason = "warn"
+cognitive_complexity = "warn"
+excessive_nesting = "warn"
diff --git a/clippy.toml b/clippy.toml
new file mode 100644
index 0000000..a1a18f9
--- /dev/null
+++ b/clippy.toml
@@ -0,0 +1,3 @@
+too-many-arguments-threshold = 3
+excessive-nesting-threshold = 2
+cognitive-complexity-threshold = 15
diff --git a/lefthook.yml b/lefthook.yml
index 395b7ca..d9f30a1 100644
--- a/lefthook.yml
+++ b/lefthook.yml
@@ -23,3 +23,11 @@ pre-commit:
       run: cargo clippy -- -D warnings
     ls-lint:
       run: ls_lint
+    file-length:
+      glob: "*.rs"
+      run: |
+        for f in {staged_files}; do
+          n=$(wc -l < "$f")
+          [ "$n" -le 500 ] || { echo "$f: $n lines (max 500)"; fail=1; }
+        done
+        exit ${fail:-0}