diff --git a/tests/unit_tests/sql/parse_tests.py b/tests/unit_tests/sql/parse_tests.py
index 61dca68e997..09313a1f77e 100644
--- a/tests/unit_tests/sql/parse_tests.py
+++ b/tests/unit_tests/sql/parse_tests.py
@@ -1195,12 +1195,13 @@ def test_with_clause_containing_union_is_not_mutating(engine: str) -> None:
 
 def test_with_clause_containing_union_all_is_not_mutating_oracle() -> None:
     """
-    Companion to test_with_clause_containing_union_is_not_mutating: the
-    original bug report (#25659) used the exact Oracle-flavored shape below
-    (``SYSDATE FROM DUAL`` is the Oracle no-op for "now"). Pinning the
-    verbatim repro guards against a future dialect-specific regression that
-    a generic ``SELECT 1`` test might miss.
-    """
+    Companion to test_with_clause_containing_union_is_not_mutating: exercises
+    UNION ALL (a sibling of UNION whose per-dialect sqlglot AST shape can
+    diverge) on the Oracle-flavored ``SYSDATE FROM DUAL`` form from #25659.
+    UNION is covered by the parametrized test above; this guards against a
+    UNION-ALL-specific or Oracle-shape-specific regression that a generic
+    ``SELECT 1 UNION SELECT 2`` test might miss.
+"""
     sql = """
     WITH SET1 AS (SELECT SYSDATE FROM DUAL UNION ALL SELECT SYSDATE FROM DUAL),
          SET2 AS (SELECT * FROM SET1)