Improve restore-key documentation

README.md

@@ -38,7 +38,8 @@ Create a workflow `.yml` file in your repositories `.github/workflows` directory
 
 * `path` - A list of files, directories, and wildcard patterns to cache and restore. See [`@actions/glob`](https://github.com/actions/toolkit/tree/main/packages/glob) for supported patterns. 
 * `key` - An explicit key for restoring and saving the cache
-* `restore-keys` - An ordered list of keys to use for restoring the cache if no cache hit occurred for key
+* `restore-keys` - An ordered list of keys to use for restoring stale cache if no cache hit occurred for key. Note
+`cache-hit` returns false in this case.
 
 ### Outputs
 

action.yml

@@ -9,7 +9,7 @@ inputs:
     description: 'An explicit key for restoring and saving the cache'
     required: true
   restore-keys:
-    description: 'An ordered list of keys to use for restoring the cache if no cache hit occurred for key'
+    description: 'An ordered list of keys to use for restoring stale cache if no cache hit occurred for key. Note `cache-hit` returns false in this case.'
     required: false
   upload-chunk-size:
     description: 'The chunk size used to split up large files during upload, in bytes'