diff --git a/promgen/models.py b/promgen/models.py
index d3606aa7..d99467a8 100644
--- a/promgen/models.py
+++ b/promgen/models.py
@@ -495,11 +495,12 @@ def save(self, *args, **kwargs):
                 self.annotations["rule"] = resolve_domain("rule-detail", pk=self.pk)
                 super().save(*args, **kwargs)
             else:
-                # When creating a new rule, the primary key is typically not available until the instance is saved to the database.
+                # When creating a new rule, the primary key is typically not available until the
+                # instance is saved to the database.
                 # Therefore, we save it first then set annotations["rule"] and save again.
                 super().save(*args, **kwargs)
                 self.annotations["rule"] = resolve_domain("rule-detail", pk=self.pk)
-                super().save(update_fields=['annotations'])
+                super().save(update_fields=["annotations"])
 
 
 class AlertLabel(models.Model):
diff --git a/promgen/tests/test_models.py b/promgen/tests/test_models.py
index 3aaf4819..33d42362 100644
--- a/promgen/tests/test_models.py
+++ b/promgen/tests/test_models.py
@@ -38,8 +38,9 @@ def test_validators(self):
             )
 
     @mock.patch("django.dispatch.dispatcher.Signal.send")
-    def test_custom_save_rule(self, mock_post):
-        # Check if annotation["rule"] is automatically set to be {domain}/rule/{id} when creating a new rule
+    def test_rule_annotation(self, mock_post):
+        # Check if annotation["rule"] is automatically set to be {domain}/rule/{id} when creating a
+        # new rule
         rule = models.Rule(
             name="example-rule",
             content_type=ContentType.objects.get_for_model(models.Site),
@@ -50,18 +51,21 @@ def test_custom_save_rule(self, mock_post):
         rule.save()
         self.assertEqual(resolve_domain("rule-detail", rule.pk), rule.annotations["rule"])
 
-        # Check if annotation["rule"] is automatically set to be {domain}/rule/{id} when updating an existed rule
+        # Check if annotation["rule"] is automatically set to be {domain}/rule/{id} when updating an
+        # existed rule
         rule.name = "another-example-rule"
         rule.annotations["rule"] = "another-annotation-value"
         rule.save()
         self.assertEqual(resolve_domain("rule-detail", rule.pk), rule.annotations["rule"])
 
-        # Check if annotation["rule"] is still set to be {domain}/rule/{id} when trying to remove annotation["rule"]
+        # Check if annotation["rule"] is still set to be {domain}/rule/{id} when trying to remove
+        # annotation["rule"]
         rule.annotations["rule"] = None
         rule.save()
         self.assertEqual(resolve_domain("rule-detail", rule.pk), rule.annotations["rule"])
 
-        # Check if annotation["rule"] of new rule is automatically set to be {domain}/rule/{id}  when cloning an existed rule
+        # Check if annotation["rule"] of new rule is automatically set to be {domain}/rule/{id}
+        # when cloning an existed rule
         new_rule = rule.copy_to(content_type="service", object_id=2)
         self.assertEqual(resolve_domain("rule-detail", rule.pk), rule.annotations["rule"])
         self.assertEqual(resolve_domain("rule-detail", new_rule.pk), new_rule.annotations["rule"])