diff --git a/core/lib/Drupal/Core/Entity/DisplayComponentHandlerInterface.php b/core/lib/Drupal/Core/Entity/DisplayComponentHandlerInterface.php
index f9fce57fe7..f628776e99 100644
--- a/core/lib/Drupal/Core/Entity/DisplayComponentHandlerInterface.php
+++ b/core/lib/Drupal/Core/Entity/DisplayComponentHandlerInterface.php
@@ -3,7 +3,7 @@
 namespace Drupal\Core\Entity;
 
 /**
- * Provides a base class for DisplayComponent plugins.
+ * Provides a interface for DisplayComponent plugins.
  */
 interface DisplayComponentHandlerInterface {
 
@@ -16,7 +16,7 @@ interface DisplayComponentHandlerInterface {
    * @return bool
    *   TRUE if the display component handler provides the component.
    */
-  public function hasElement($name);
+  public function hasElement($name): bool;
 
   /**
    * Prepares the options before they are stored.
@@ -29,7 +29,7 @@ public function hasElement($name);
    * @return array
    *   Massaged component options.
    */
-  public function preSave($name, array $options);
+  public function preSave($name, array $options): array;
 
   /**
    * Prepares the display options after they are retrieved from the storage.
@@ -42,7 +42,7 @@ public function preSave($name, array $options);
    *   - content: Configured components to render.
    *   - hidden: Configured components to hide from render.
    */
-  public function postLoad(array $properties);
+  public function postLoad(array $properties): array;
 
   /**
    * Sets the context for the rendering component.
@@ -52,10 +52,10 @@ public function postLoad(array $properties);
    *   following parameters should be set:
    *   - entity_type: The type of entity.
    *   - bundle: The entity bundle.
-   *   - view_mode: The entity view mode (default, full).
-   *   - display_context: The type of the display to use (view or form).
+   *   - view_mode: The entity view mode; e.g., 'default', 'full'.
+   *   - display_context: The type of the display to use; e.g., 'view', 'form'.
    */
-  public function setContext(array $context);
+  public function setContext(array $context): array;
 
   /**
    * Returns the render plugin for the display component.
@@ -65,8 +65,8 @@ public function setContext(array $context);
    * @param array $options
    *   An array of configuration options to instantiate the render plugin.
    *
-   * @return mixed
-   *   The object to render the component or null.
+   * @return Drupal\Core\Entity\Plugin\DisplayComponent\FieldDisplayComponentHandler|null
+   *   The object to render the component or NULL.
    */
   public function getRenderer($name, array $options);
 
diff --git a/core/lib/Drupal/Core/Entity/EntityDisplayBase.php b/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
index 6813c50cf4..df89b69aca 100644
--- a/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
@@ -122,7 +122,7 @@ abstract class EntityDisplayBase extends ConfigEntityBase implements EntityDispl
   protected $renderer;
 
   /**
-   * A mapping of display elements and its corresponding handler.
+   * An array of handlers keyed by their display element names.
    */
   protected $handlers;
 
diff --git a/core/lib/Drupal/Core/Entity/EntityViewBuilder.php b/core/lib/Drupal/Core/Entity/EntityViewBuilder.php
index 9da338c096..980f006aa7 100644
--- a/core/lib/Drupal/Core/Entity/EntityViewBuilder.php
+++ b/core/lib/Drupal/Core/Entity/EntityViewBuilder.php
@@ -88,7 +88,7 @@ class EntityViewBuilder extends EntityHandlerBase implements EntityHandlerInterf
   protected $entityFieldManager;
 
   /**
-   * The entity field manager.
+   * The formatter plugin manager.
    *
    * @var \Drupal\Core\Field\FormatterPluginManager
    */
diff --git a/core/lib/Drupal/Core/Entity/Plugin/DisplayComponent/ExtraFieldDisplayComponentHandler.php b/core/lib/Drupal/Core/Entity/Plugin/DisplayComponent/ExtraFieldDisplayComponentHandler.php
index 171d6b3406..c043fb426b 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/DisplayComponent/ExtraFieldDisplayComponentHandler.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/DisplayComponent/ExtraFieldDisplayComponentHandler.php
@@ -11,7 +11,7 @@
  * Provides a component handler to manage entity extra fields.
  *
  * @DisplayComponent(
- *   id = "extra_field"
+ *   id = "extra_field",
  * )
  */
 class ExtraFieldDisplayComponentHandler extends DisplayComponentHandlerBase implements ContainerFactoryPluginInterface {
@@ -24,7 +24,7 @@ class ExtraFieldDisplayComponentHandler extends DisplayComponentHandlerBase impl
   protected $entityFieldManager;
 
   /**
-   * Constructs a FieldDisplayComponentHandler object.
+   * Constructs a ExtraFieldDisplayComponentHandler object.
    *
    * @param array $configuration
    *   A configuration array containing information about the plugin instance.
diff --git a/core/lib/Drupal/Core/Entity/Plugin/DisplayComponent/FieldDisplayComponentHandler.php b/core/lib/Drupal/Core/Entity/Plugin/DisplayComponent/FieldDisplayComponentHandler.php
index 18f75d6688..c39c6308c5 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/DisplayComponent/FieldDisplayComponentHandler.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/DisplayComponent/FieldDisplayComponentHandler.php
@@ -173,6 +173,9 @@ public function hasElement($name) {
 
   /**
    * Returns the field definition of a field.
+   *
+   * @return \Drupal\Core\Field\FieldDefinitionInterface
+   *   The field definition.
    */
   protected function getFieldDefinition($field_name) {
     $definitions = $this->getDisplayableFields();
@@ -181,6 +184,9 @@ protected function getFieldDefinition($field_name) {
 
   /**
    * Returns the definitions of the fields that are candidate for display.
+   *
+   * @return array
+   *   Returns the fields definitions.
    */
   protected function getDisplayableFields() {
     $entity_type = $this->context['entity_type'];
diff --git a/core/lib/Drupal/Core/Entity/entity.api.php b/core/lib/Drupal/Core/Entity/entity.api.php
index 0c54dbbcc0..ae416f0238 100644
--- a/core/lib/Drupal/Core/Entity/entity.api.php
+++ b/core/lib/Drupal/Core/Entity/entity.api.php
@@ -2264,7 +2264,7 @@ function hook_entity_extra_field_info_alter(&$info) {
  * @param string[] $plugins
  *   An array of all the existing plugin definitions, passed by reference.
  *
- * @see DisplayComponentHandlerPluginManager
+ * @see \Drupal\Core\Entity\DisplayComponentHandlerPluginManager
  */
 function hook_display_component_handler_info_alter(array &$plugins) {
   $plugins['some_plugin']['label'] = t('Better name');