diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 1d8c630..5c85622 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2364,6 +2364,20 @@ function _drupal_shutdown_function() {
 /**
  * Compares the memory required for an operation to the available memory.
  *
+ * @param $required
+ *   The memory required for the operation, expressed as a number of bytes with
+ *   optional SI or IEC binary unit prefix (e.g. 2, 3K, 5MB, 10G, 6GiB, 8bytes,
+ *   9mbytes).
+ * @param $memory_limit
+ *   (optional) The memory limit for the operation, expressed as a number of
+ *   bytes with optional SI or IEC binary unit prefix (e.g. 2, 3K, 5MB, 10G,
+ *   6GiB, 8bytes, 9mbytes). If no value is passed, the current PHP
+ *   memory_limit will be used. Defaults to NULL.
+ *
+ * @return
+ *   TRUE if there is sufficient memory to allow the operation, or FALSE
+ *   otherwise.
+ *
  * @deprecated 8.0
  *   Use \Drupal\Component\Utility\Environment::checkMemoryLimit().
  */