diff --git a/core/lib/Drupal/Core/Executable/ExecutablePluginBase.php b/core/lib/Drupal/Core/Executable/ExecutablePluginBase.php
index 3c36eac51236..547724a50f6f 100644
--- a/core/lib/Drupal/Core/Executable/ExecutablePluginBase.php
+++ b/core/lib/Drupal/Core/Executable/ExecutablePluginBase.php
@@ -15,7 +15,7 @@ abstract class ExecutablePluginBase extends ContextAwarePluginBase implements Ex
    *
    * @todo: This needs to go into an interface.
    *
-   * @return array
+   * @return \Drupal\Core\TypedData\DataDefinitionInterface[]
    *   An array of typed data definitions describing available configuration
    *   options, keyed by option name.
    */
@@ -30,9 +30,12 @@ abstract class ExecutablePluginBase extends ContextAwarePluginBase implements Ex
   /**
    * Gets the definition of a configuration option.
    *
+   * @param string $key
+   *   The key of the configuration option to get.
+   *
    * @todo: This needs to go into an interface.
    *
-   * @return array
+   * @return \Drupal\Core\TypedData\DataDefinitionInterface|false
    *   The typed data definition describing the configuration option, or FALSE
    *   if the option does not exist.
    */
@@ -71,6 +74,9 @@ abstract class ExecutablePluginBase extends ContextAwarePluginBase implements Ex
    *
    * @return \Drupal\Core\Executable\ExecutablePluginBase
    *   The executable object for chaining.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\PluginException
+   *   If the provided configuration value does not pass validation.
    */
   public function setConfig($key, $value) {
     if ($definition = $this->getConfigDefinition($key)) {