diff --git a/core/modules/system/src/Tests/Cache/AssertPageCacheContextsAndTagsTrait.php b/core/modules/system/src/Tests/Cache/AssertPageCacheContextsAndTagsTrait.php
index c943c98..250e43a 100644
--- a/core/modules/system/src/Tests/Cache/AssertPageCacheContextsAndTagsTrait.php
+++ b/core/modules/system/src/Tests/Cache/AssertPageCacheContextsAndTagsTrait.php
@@ -26,12 +26,12 @@ protected function enablePageCaching() {
   }
 
   /**
-   * Gets a specifc header value as array.
+   * Gets a specific header value as array.
    *
    * @param string $header_name
    *   The header name.
    *
-   * @return array
+   * @return string[]
    *   The header value, potentially exploded by spaces.
    */
   protected function getCacheHeaderValues($header_name) {
@@ -83,9 +83,9 @@ protected function assertPageCacheContextsAndTags(Url $url, array $expected_cont
   }
 
   /**
-   * Ensures that some cache tags got sent in the latest response.
+   * Ensures that some cache tags are present in the current response.
    *
-   * @param array $expected_tags
+   * @param string[] $expected_tags
    *   The expected tags.
    */
   protected function assertCacheTags(array $expected_tags) {
@@ -98,9 +98,9 @@ protected function assertCacheTags(array $expected_tags) {
   }
 
   /**
-   * Ensures that some cache contexts got sent in the latest response.
+   * Ensures that some cache contexts are present in the current response.
    *
-   * @param array $expected_contexts
+   * @param string[] $expected_contexts
    *   The expected cache contexts.
    */
   protected function assertCacheContexts(array $expected_contexts) {