diff --git a/vertical_tabs_example/src/Controller/VerticalTabsExampleController.php b/vertical_tabs_example/src/Controller/VerticalTabsExampleController.php
index cc732dd..0a14bbc 100644
--- a/vertical_tabs_example/src/Controller/VerticalTabsExampleController.php
+++ b/vertical_tabs_example/src/Controller/VerticalTabsExampleController.php
@@ -14,7 +14,7 @@ class VerticalTabsExampleController {
   use DescriptionTemplateTrait;
 
   /**
-   * {%inheritdoc}.
+   * {@inheritdoc}
    */
   protected function getModuleName() {
     return 'vertical_tabs_example';
diff --git a/vertical_tabs_example/src/Tests/VerticalTabsExampleTest.php b/vertical_tabs_example/src/Tests/VerticalTabsExampleTest.php
index 735a3c0..3d31aa2 100644
--- a/vertical_tabs_example/src/Tests/VerticalTabsExampleTest.php
+++ b/vertical_tabs_example/src/Tests/VerticalTabsExampleTest.php
@@ -18,7 +18,7 @@ class VerticalTabsExampleTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = array('node' , 'vertical_tabs_example');
+  public static $modules = ['vertical_tabs_example'];
 
   /**
    * Tests the menu paths defined in vertical_tabs_example module.
diff --git a/vertical_tabs_example/templates/description.html.twig b/vertical_tabs_example/templates/description.html.twig
index c0a7fad..083113e 100644
--- a/vertical_tabs_example/templates/description.html.twig
+++ b/vertical_tabs_example/templates/description.html.twig
@@ -8,8 +8,11 @@
 {% set content_url = path('node.add_page') %}
 
 {% trans %}
-<p>The Vertical Tabs Example shows how a custom module can add a vertical tab
-to a node edit form,and support its summary field with JavaScript. To see the
-effects of this module, <a href= {{ content_url }}>add a piece of content</a>
-and look at the set of tabs beside. </p>
+<p>The Vertical Tabs Example shows how a custom module can add a vertical tab to
+  a node edit form and update its summary field with JavaScript.</p>
+<p>To see the effects of this module, <a href= {{ content_url }}>add a piece of
+  content</a> and look at the set of tabs beside. </p>
+<p>Note that this behavior won't work with the "Seven" administration theme that
+  is enabled by default. You'll need to change the administration theme to be
+  another one.</p>
 {% endtrans %}
diff --git a/vertical_tabs_example/vertical_tabs_example.info.yml b/vertical_tabs_example/vertical_tabs_example.info.yml
index 73fa8de..8cc15d2 100644
--- a/vertical_tabs_example/vertical_tabs_example.info.yml
+++ b/vertical_tabs_example/vertical_tabs_example.info.yml
@@ -4,4 +4,5 @@ description: 'Show how to use vertical tabs for enhancing user experience.'
 package: Example modules
 core: 8.x
 dependencies:
-  - examples
+  - drupal:node
+  - examples:examples
diff --git a/vertical_tabs_example/vertical_tabs_example.module b/vertical_tabs_example/vertical_tabs_example.module
index eedd8ef..72292c0 100644
--- a/vertical_tabs_example/vertical_tabs_example.module
+++ b/vertical_tabs_example/vertical_tabs_example.module
@@ -11,6 +11,10 @@ use Drupal\Core\Form\FormStateInterface;
  * Implements hook_form_alter().
  */
 function vertical_tabs_example_form_node_form_alter(array &$form, FormStateInterface $form_state) {
+  // Vertical tabs provide its most usable appearance when they are used to
+  // include a summary of the information contained in the details. To do this,
+  // we attach additional JavaScript to handle changing the summary when form
+  // settings are changed.
   $form['#attached']['library'][] = 'vertical_tabs_example/vertical_tabs_example';
   // Create a details field that will be included in the vertical tab.
   $form['vertical_tabs_example'] = [
@@ -24,11 +28,8 @@ function vertical_tabs_example_form_node_form_alter(array &$form, FormStateInter
     // The #group value must match the name of the vertical tabs element.
     // In most cases, this is 'additional_settings'.
     '#group' => 'advanced',
-    // Vertical tabs provide its most usable appearance when they are used to
-    // include a summary of the information contained in the details. To do
-    // this, we attach additional JavaScript to handle changing the summary
-    // when form settings are changed.
-    ];
+  ];
+
   // The form elements below provide a demonstration of how a details
   // summary can be displayed in a collapsed tab.
   //
@@ -39,23 +40,23 @@ function vertical_tabs_example_form_node_form_alter(array &$form, FormStateInter
     '#title' => t('Change this setting'),
     '#default_value' => FALSE,
   ];
-  
+
   // This container will be used to store the whole form for our custom
-  // settings. This way, showing/hiding the form using javascript is easier,
+  // settings. This way, showing/hiding the form using JavaScript is easier,
   // as only one element should be set visible.
   $form['vertical_tabs_example']['vertical_tabs_examplecontainer'] = [
     '#type' => 'container',
     '#parents' => ['vertical_tabs_example'],
     '#states' => [
-       'invisible' => [
+      'invisible' => [
           // If the checkbox is not enabled, show the container.
-          'input[name="vertical_tabs_example[enabled]"]' => ['checked' => FALSE],
-       ],
+        'input[name="vertical_tabs_example[enabled]"]' => ['checked' => FALSE],
+      ],
     ],
   ];
-  
-    // The string of this textfield will be shown as summary in the vertical
-    // tab.
+
+  // The string of this textfield will be shown as summary in the vertical
+  // tab.
   $form['vertical_tabs_example']['vertical_tabs_examplecontainer']['custom_setting'] = [
     '#type' => 'textfield',
     '#title' => t('Use this setting instead'),