diff --git a/tests/ext/workflow/test_mcp_schema.py b/tests/ext/workflow/test_mcp_schema.py
index 6f369b712..6bf7871e4 100644
--- a/tests/ext/workflow/test_mcp_schema.py
+++ b/tests/ext/workflow/test_mcp_schema.py
@@ -151,6 +151,25 @@ def test_oneof_nullable_integer(self):
         instance = Model(count=5)
         self.assertEqual(instance.count, 5)
 
+    def test_anyof_array_variant(self):
+        schema = {
+            'type': 'object',
+            'properties': {
+                'tags': {
+                    'anyOf': [
+                        {'type': 'array', 'items': {'type': 'integer'}},
+                        {'type': 'null'},
+                    ]
+                }
+            },
+            'required': ['tags'],
+        }
+        Model = create_pydantic_model_from_schema(schema, 'ArrayVariantModel')
+        instance = Model(tags=[1, 2, 3])
+        self.assertEqual(instance.tags, [1, 2, 3])
+        instance2 = Model(tags=None)
+        self.assertIsNone(instance2.tags)
+
 
 class TestKwargsUnwrapping(unittest.TestCase):
     """Tests for the kwargs wrapper unwrapping pattern."""
@@ -228,6 +247,12 @@ def test_returns_pydantic_model_subclass(self):
         Model = create_pydantic_model_from_schema(schema, 'SubclassCheck')
         self.assertTrue(issubclass(Model, BaseModel))
 
+    def test_invalid_schema_raises_value_error(self):
+        schema = {'type': 'object', 'properties': {'x': 'not-a-dict'}}
+        with self.assertRaises(ValueError) as ctx:
+            create_pydantic_model_from_schema(schema, 'InvalidModel')
+        self.assertIn('Invalid schema', str(ctx.exception))
+
     def test_model_name_set(self):
         schema = {
             'type': 'object',