diff --git a/pytools/tag.py b/pytools/tag.py
index dd458af79b28c0f253826d962cc5e0f7d3bf47a1..9b44b8513d086d45bcf4ad7f6587a925a4e3599a 100644
--- a/pytools/tag.py
+++ b/pytools/tag.py
@@ -128,12 +128,12 @@ class Tag:
 
 class UniqueTag(Tag):
     """
-    Parent class intended for subclassing.
+    A superclass for tags that are unique on each `Taggable`.
 
     Each instance of :class:`Taggable` may have no more than one
     instance of each subclass of :class:`UniqueTag` in its
     set of `tags`. Multiple `UniqueTag` instances of
-    different subclasses are allowed.
+    different (immediate) subclasses are allowed.
     """
     pass