diff --git a/core/lib/Drupal/Core/Annotation/QueueWorker.php b/core/lib/Drupal/Core/Annotation/QueueWorker.php
index 8b5df53..5409f4e 100644
--- a/core/lib/Drupal/Core/Annotation/QueueWorker.php
+++ b/core/lib/Drupal/Core/Annotation/QueueWorker.php
@@ -23,10 +23,15 @@
  * the queue in this hook if you want, however, you need to take care of
  * processing the items in the queue in that case.
  *
- * @see hook_cron()
- * @see hook_queue_info_alter()
+ * Plugin Namespace: Plugin\QueueWorker
+ *
+ * For a working example, see
+ * \Drupal\aggregator\Plugin\QueueWorker\AggregatorRefresh.
+ *
  * @see \Drupal\Core\Queue\QueueWorkerInterface
- * @see \Drupal\Core\Queue\QueueWorkerManagerInterface
+ * @see \Drupal\Core\Queue\QueueWorkerBase
+ * @see \Drupal\Core\Queue\QueueWorkerManager
+ * @see plugin_api
  *
  * @Annotation
  */
diff --git a/core/lib/Drupal/Core/Queue/QueueWorkerBase.php b/core/lib/Drupal/Core/Queue/QueueWorkerBase.php
index 1a3dd44..7fe3417 100644
--- a/core/lib/Drupal/Core/Queue/QueueWorkerBase.php
+++ b/core/lib/Drupal/Core/Queue/QueueWorkerBase.php
@@ -10,7 +10,12 @@
 use Drupal\Component\Plugin\PluginBase;
 
 /**
- * Provides a basis for queue worker plugins.
+ * Provides a base implementation for a QueueWorker plugin.
+ *
+ * @see \Drupal\Core\Queue\QueueWorkerInterface
+ * @see \Drupal\Core\Queue\QueueWorkerManager
+ * @see \Drupal\Core\Annotation\QueueWorker
+ * @see plugin_api
  */
 abstract class QueueWorkerBase extends PluginBase implements QueueWorkerInterface {
 
diff --git a/core/lib/Drupal/Core/Queue/QueueWorkerInterface.php b/core/lib/Drupal/Core/Queue/QueueWorkerInterface.php
index 376e5ad..ee4124a 100644
--- a/core/lib/Drupal/Core/Queue/QueueWorkerInterface.php
+++ b/core/lib/Drupal/Core/Queue/QueueWorkerInterface.php
@@ -10,13 +10,35 @@
 use Drupal\Component\Plugin\PluginInspectionInterface;
 
 /**
- * Defines an interface for queue workers.
+ * Defines an interface for a QueueWorker plugin.
+ *
+ * @see \Drupal\Core\Queue\QueueWorkerBase
+ * @see \Drupal\Core\Queue\QueueWorkerManager
+ * @see \Drupal\Core\Annotation\QueueWorker
+ * @see plugin_api
  */
 interface QueueWorkerInterface extends PluginInspectionInterface {
 
   /**
+   * Works on a single queue item.
+   *
    * @param mixed $data
-   *   Arbitrary data associated with the queued item being processed.
+   *   The data that was passed to
+   *   \Drupal\Core\Queue\QueueInterface::createItem() when the item was queued.
+   *
+   * @throws \Exception
+   *   The worker callback may throw an exception to indicate there was a
+   *   problem. The cron process will log the exception, and leave the item in
+   *   the queue to be processed again later.
+   * @throws \Drupal\Core\Queue\SuspendQueueException
+   *   More specifically, a SuspendQueueException should be thrown when the
+   *   callback is aware that the problem will affect all subsequent workers of
+   *   its queue. For example, a callback that makes HTTP requests may find that
+   *   the remote server is not responding. The cron process will behave as with
+   *   a normal Exception, and in addition will not attempt to process further
+   *   items from the current item's queue during the current cron run.
+   *
+   * @see \Drupal\Core\Cron::run()
    */
   public function processItem($data);
 
diff --git a/core/lib/Drupal/Core/Queue/QueueWorkerManager.php b/core/lib/Drupal/Core/Queue/QueueWorkerManager.php
index 6c140a8..6339065 100644
--- a/core/lib/Drupal/Core/Queue/QueueWorkerManager.php
+++ b/core/lib/Drupal/Core/Queue/QueueWorkerManager.php
@@ -13,6 +13,11 @@
 
 /**
  * Defines the queue worker manager.
+ *
+ * @see \Drupal\Core\Queue\QueueWorkerInterface
+ * @see \Drupal\Core\Queue\QueueWorkerBase
+ * @see \Drupal\Core\Annotation\QueueWorker
+ * @see plugin_api
  */
 class QueueWorkerManager extends DefaultPluginManager implements QueueWorkerManagerInterface {
 
diff --git a/core/modules/aggregator/aggregator.module b/core/modules/aggregator/aggregator.module
index b080149..7ef3bea 100644
--- a/core/modules/aggregator/aggregator.module
+++ b/core/modules/aggregator/aggregator.module
@@ -6,7 +6,6 @@
  */
 
 use Drupal\aggregator\Entity\Feed;
-use Drupal\aggregator\FeedInterface;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Routing\RouteMatchInterface;
 
diff --git a/core/modules/locale/src/Plugin/QueueWorker/LocaleTranslation.php b/core/modules/locale/src/Plugin/QueueWorker/LocaleTranslation.php
index 50e197a..a850b0d 100644
--- a/core/modules/locale/src/Plugin/QueueWorker/LocaleTranslation.php
+++ b/core/modules/locale/src/Plugin/QueueWorker/LocaleTranslation.php
@@ -14,6 +14,8 @@
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
+ * Executes interface translation queue tasks.
+ *
  * @QueueWorker(
  *   id = "locale_translation",
  *   title = @Translation("Update translations"),