diff --git a/src/MigrateExecutable.php b/src/MigrateExecutable.php
index a0c3377..2b6b0f3 100644
--- a/src/MigrateExecutable.php
+++ b/src/MigrateExecutable.php
@@ -494,7 +494,13 @@ class MigrateExecutable extends MigrateExecutableBase {
   }
 
   /**
+   * Returns all source ids.
+   *
    * @param \Drupal\migrate\Plugin\MigrateSourceInterface $source
+   *   The source.
+   *
+   * @return array
+   *   The source id fields and their values.
    */
   public function sourceIds($source) {
     $ids = [];
@@ -508,6 +514,14 @@ class MigrateExecutable extends MigrateExecutableBase {
    * Generator for source ids.
    *
    * @param \Drupal\migrate\Plugin\MigrateSourceInterface $source
+   *   The source.
+   *
+   * @codingStandardsIgnoreStart
+   *
+   * @return \Generator
+   *   Source id fields and values.
+   *
+   * @codingStandardsIgnoreEnd
    */
   protected function idList($source) {
     $source->rewind();