diff --git a/core/modules/system/src/Plugin/Block/SystemMenuBlock.php b/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
index 781d257..15cc5d0 100644
--- a/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
+++ b/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
@@ -95,10 +95,10 @@ public function blockForm($form, FormStateInterface $form_state) {
 
     $form['menu_levels']['level'] = array(
       '#type' => 'select',
-      '#title' => $this->t('Start at menu level'),
+      '#title' => $this->t('Initial menu level'),
       '#default_value' => $config['level'],
       '#options' => $options,
-      '#description' => $this->t('By selecting menu level 1, this menu will always be visible. By selecting menu level 2 or lower, this menu will only be visible if the menu item for the current page is at the selected starting level or is nested below a menu item at that starting level.'),
+      '#description' => $this->t('The menu will only be visible if the menu item for the current page is at or below the selected starting level. Select level 1 to always keep this menu visible.'),
       '#required' => TRUE,
     );
 
@@ -109,7 +109,7 @@ public function blockForm($form, FormStateInterface $form_state) {
       '#title' => $this->t('Maximum number of menu levels to display'),
       '#default_value' => $config['depth'],
       '#options' => $options,
-      '#description' => $this->t('If the starting menu level is 1, and the maximum number of menu levels displayed is 1, then only level 1 will be displayed. With starting level 2 and maximum levels of 2, then menu levels 2 and 3 can be displayed. The default setting of Unlimited places no limits on the number of menu levels that can be displayed.'),
+      '#description' => $this->t('The maximum number of menu levels to show, starting from the initial menu level. For example: with an initial level 2 and a maximum number of 3, menu levels 2, 3 and 4 can be displayed.'),
       '#required' => TRUE,
     );
 
@@ -117,7 +117,7 @@ public function blockForm($form, FormStateInterface $form_state) {
   }
 
   /**
-   * Adjusts the #parents of menu_levels to save its children at the top level
+   * Adjusts the #parents of menu_levels to save its children at the top level.
    */
   public static function processMenuLevelParents(&$element, FormStateInterface $form_state, &$complete_form) {
     array_pop($element['#parents']);
@@ -164,11 +164,11 @@ public function defaultConfiguration() {
     // 1) it is possible to set a different max age for individual blocks, since
     //    this is just the default value.
     // 2) modules can modify caching by implementing hook_block_view_alter()
-    return array(
+    return [
       'cache' => array('max_age' => Cache::PERMANENT),
       'level' => 1,
       'depth' => 0,
-    );
+    ];
   }
 
   /**