diff --git a/app/code/Magento/Backend/Block/Widget/Tabs.php b/app/code/Magento/Backend/Block/Widget/Tabs.php
index 573af01a78955..fd6c61b14dbd6 100644
--- a/app/code/Magento/Backend/Block/Widget/Tabs.php
+++ b/app/code/Magento/Backend/Block/Widget/Tabs.php
@@ -235,6 +235,7 @@ protected function _beforeToHtml()
         $this->_tabs = $this->reorderTabs();
         
         if ($this->_activeTab === null) {
+            /** @var  $tab */
             foreach ($this->_tabs as $tab) {
                 $this->_activeTab = $tab->getId();
                 break;
@@ -263,8 +264,10 @@ protected function reorderTabs()
         $position  = 100;
     
         /**
-         * @var string                                         $key
-         * @var \Magento\Backend\Block\Widget\Tab\TabInterface $tab
+         * Set the initial positions for each tab.
+         *
+         * @var string       $key
+         * @var TabInterface $tab
          */
         foreach ($this->_tabs as $key => $tab) {
             $tab->setPosition($position);
@@ -277,6 +280,12 @@ protected function reorderTabs()
         
         $positionFactor = 1;
         
+        /**
+         * Rearrange the positions by using the after tag for each tab.
+         *
+         * @var integer      $position
+         * @var TabInterface $tab
+         */
         foreach ($orderByPosition as $position => $tab) {
             if (!$tab->getAfter() || !in_array($tab->getAfter(), array_keys($orderByIdentity))) {
                 $positionFactor = 1;