diff --git a/core/modules/system/src/Tests/Entity/EntitySchemaTest.php b/core/modules/system/src/Tests/Entity/EntitySchemaTest.php
index e7312bf..695c0e8 100644
--- a/core/modules/system/src/Tests/Entity/EntitySchemaTest.php
+++ b/core/modules/system/src/Tests/Entity/EntitySchemaTest.php
@@ -140,10 +140,11 @@ public function testModifyingTranslatableColumnSchema() {
   }
 
   /**
-   * Tests that after uninstalling a module the fields are removed from the
-   * schema.
+   * Tests fields from an uninstalled module are removed from the schema.
    */
   public function testCleanUpStorageDefinition() {
+    // Find all the entity types provided by the entity_test module and install
+    // the schema for them.
     $entities = \Drupal::entityManager()->getDefinitions();
     foreach ($entities as $name => $definition) {
       if ($definition->getProvider() == 'entity_test') {
@@ -151,14 +152,16 @@ public function testCleanUpStorageDefinition() {
       };
     }
 
+    // Uninstall the entity_test module.
     $this->container->get('module_installer')->uninstall(array('entity_test'));
 
-    // Ensure that all storage defintions have been removed from the schema.
+    // Get a list of all the entities in the schema.
     $key_value_store = \Drupal::keyValue('entity.storage_schema.sql');
     $schema = $key_value_store->getAll();
 
     $item_count = 0;
 
+    // Count the storage definitions that begin with entity_test.
     foreach (array_keys($schema) as $storage_definition_name) {
       $entity_item = substr($storage_definition_name, 0, strpos($storage_definition_name, '.'));
       if ($entity_item == 'entity_test') {
@@ -166,8 +169,8 @@ public function testCleanUpStorageDefinition() {
       }
     }
 
-    $this->assertEqual($item_count, 0, 'After uninstallation the schema' .
-      'still contains fields for the the comment entity.');
+    // Ensure that all storage definitions have been removed from the schema.
+    $this->assertEqual($item_count, 0, 'After uninstalling entity_test module the schema still contains fields for the the entity_test entity.');
   }
 
 }