diff --git a/tests/cron/test_cronjob_schema.py b/tests/cron/test_cronjob_schema.py
new file mode 100644
index 00000000000..ec98c9479de
--- /dev/null
+++ b/tests/cron/test_cronjob_schema.py
@@ -0,0 +1,41 @@
+"""Tests for the cronjob tool schema shape.
+
+Guards the description text that flags ``schedule`` (and ``prompt``) as
+REQUIRED for ``action=create`` — the load-bearing fix for description-driven
+models (e.g. Grok) that omit schedule when the schema only lists ``action``
+in ``required[]``. See issue #32427 / PR #32448.
+"""
+
+from __future__ import annotations
+
+
+def test_cronjob_schema_action_description_flags_create_requirements():
+    """`action` description must state schedule + prompt are required for create."""
+    from tools.cronjob_tools import CRONJOB_SCHEMA
+
+    action_desc = CRONJOB_SCHEMA["parameters"]["properties"]["action"]["description"]
+    assert "action=create" in action_desc
+    assert "schedule" in action_desc
+    assert "REQUIRED" in action_desc
+
+
+def test_cronjob_schema_schedule_description_flags_required_for_create():
+    """`schedule` description must explicitly state REQUIRED for action=create."""
+    from tools.cronjob_tools import CRONJOB_SCHEMA
+
+    schedule_desc = CRONJOB_SCHEMA["parameters"]["properties"]["schedule"]["description"]
+    assert "REQUIRED" in schedule_desc
+    assert "action=create" in schedule_desc
+
+
+def test_cronjob_schema_required_array_unchanged():
+    """`required[]` stays minimal — `action` only.
+
+    The schema intentionally does NOT promote schedule/prompt into the
+    top-level required array because they're only mandatory for
+    action=create, not for list/remove/pause/etc. The description text
+    carries the conditional requirement instead.
+    """
+    from tools.cronjob_tools import CRONJOB_SCHEMA
+
+    assert CRONJOB_SCHEMA["parameters"]["required"] == ["action"]