diff --git a/docs/CATALOG.md b/docs/CATALOG.md
index 0ee207c..465869c 100644
--- a/docs/CATALOG.md
+++ b/docs/CATALOG.md
@@ -155,6 +155,7 @@ hflow curate --sql-file query.sql \
 
 Pass exactly one of the positional SQL string or `--sql-file`; passing both or
 neither is an error.
+The curate() function accepts exactly one SELECT statement
 
 The manifest is written **manifest-last**: to a temp file, renamed into place
 only after the query completed, so a partial manifest is unreachable.
diff --git a/tests/test_catalog_curation.py b/tests/test_catalog_curation.py
index 69aa964..ecdae80 100644
--- a/tests/test_catalog_curation.py
+++ b/tests/test_catalog_curation.py
@@ -837,6 +837,21 @@ def test_constrained_connection_confines_sql_to_the_catalog(tmp_path: Path) -> N
         False,
         id="legitimate-single-select",
     ),
+    pytest.param(
+        "PIVOT episodes ON status USING count(*)",
+        True,
+        id="pivot",  # DuckDB secretly expands this to CREATE then SELECT
+    ),
+    pytest.param(
+        "DESCRIBE SELECT episode_id FROM episodes",
+        False,
+        id="describe",
+    ),
+    pytest.param(
+        "SUMMARIZE SELECT episode_id FROM episodes",
+        False,
+        id="summarize",
+    ),
 ]