diff --git a/core/modules/contextual/src/ContextualController.php b/core/modules/contextual/src/ContextualController.php
index 59a2ba0f951..58e42ecd6ba 100644
--- a/core/modules/contextual/src/ContextualController.php
+++ b/core/modules/contextual/src/ContextualController.php
@@ -16,12 +16,13 @@ class ContextualController implements ContainerInjectionInterface {
 
   /**
    * The renderer.
+   *
    * @var \Drupal\Core\Render\RendererInterface
    */
-  protected $render;
+  protected $renderer;
 
   /**
-   * Constructors a new ContextualController
+   * Constructors a new ContextualController.
    *
    * @param \Drupal\Core\Render\RendererInterface $renderer
    *   The renderer.
@@ -45,10 +46,16 @@ class ContextualController implements ContainerInjectionInterface {
    * Given a list of contextual links IDs, render them. Hence this must be
    * robust to handle arbitrary input.
    *
-   * @see contextual_preprocess()
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The Symfony request object.
    *
    * @return \Symfony\Component\HttpFoundation\JsonResponse
    *   The JSON response.
+   *
+   * @throws \Symfony\Component\HttpKernel\Exception\BadRequestHttpException
+   *   Thrown when the request contains no ids.
+   *
+   * @see contextual_preprocess()
    */
   public function render(Request $request) {
     $ids = $request->request->get('ids');