Harden MCP tool composition

tests/test_mcp_adapter.py

@@ -10,7 +10,7 @@ from rollcalc_mcp_tools import (
     calculate_roll_diameter_result,
     get_article_result,
 )
-from transport_calculation import analyze_transport
+from transport_calculation import analyze_transport, transport_presets
 
 
 class _FakeFastMCP:
@@ -51,15 +51,44 @@ class McpAdapterTests(unittest.TestCase):
                 "core_diameter_mm": 150.0,
                 "width_m": 5.8,
                 "area_weight_g_m2": 1767.2,
-                "include_roll_weight": True,
             },
             {"roll_length_m": -1.0, "core_diameter_mm": 150.0, "thickness_mm": 2.0},
         ):
             with self.subTest(arguments=arguments):
-                self.assertEqual(
-                    calculate_roll_diameter_result(**arguments),
-                    calculate_roll(arguments),
-                )
+                actual = calculate_roll_diameter_result(**arguments)
+                expected = calculate_roll({**arguments, "include_roll_weight": True})
+                if expected["status"] == "success":
+                    self.assertEqual(
+                        actual["transport_roll_inputs"]["roll_diameter_mm"],
+                        845.9,
+                    )
+                    del actual["transport_roll_inputs"]
+                self.assertEqual(actual, expected)
+
+    def test_roll_calculation_adapter_always_requests_weight_from_the_domain(self):
+        result = calculate_roll_diameter_result(
+            article_number="114030",
+            roll_length_m=15.0,
+            core_diameter_mm=100.0,
+        )
+
+        self.assertEqual(result["status"], "success")
+        self.assertIsNotNone(result["calculation"]["roll_weight_kg"])
+
+    def test_roll_calculation_adapter_uses_shared_transport_input_helper(self):
+        expected_inputs = {"roll_diameter_mm": 123.4}
+        with patch(
+            "rollcalc_mcp_tools.transport_roll_inputs_from_roll_calculation",
+            return_value=expected_inputs,
+        ) as helper:
+            result = calculate_roll_diameter_result(
+                article_number="114030",
+                roll_length_m=15.0,
+                core_diameter_mm=100.0,
+            )
+
+        helper.assert_called_once()
+        self.assertEqual(result["transport_roll_inputs"], expected_inputs)
 
     def test_transport_tool_delegates_for_preset_custom_and_invalid_cases(self):
         for arguments in (
@@ -111,6 +140,43 @@ class McpAdapterTests(unittest.TestCase):
             ],
         )
 
+    def test_server_schema_exposes_weight_and_transport_chaining_contract(self):
+        instance = mcp_server.create_server()
+        tools = instance._tool_manager._tools
+        roll_schema = tools["calculate_roll_diameter"].parameters
+        transport_tool = tools["analyze_transport_capacity"]
+        transport_schema = transport_tool.parameters
+
+        self.assertNotIn("include_roll_weight", roll_schema["properties"])
+        preset_schema = transport_schema["properties"]["transport_preset"]
+        self.assertEqual(
+            preset_schema["anyOf"][0]["enum"],
+            [preset.key for preset in transport_presets()],
+        )
+        self.assertEqual(
+            transport_schema["required"],
+            [
+                "roll_diameter_mm",
+                "core_diameter_mm",
+                "roll_width_m",
+                "roll_weight_kg",
+                "product_length_m",
+            ],
+        )
+        for field in transport_schema["required"]:
+            self.assertEqual(
+                transport_schema["properties"][field]["type"], "number"
+            )
+        description = transport_tool.description
+        for text in (
+            "first call get_article and calculate_roll_diameter",
+            "transport_roll_inputs bundle unchanged",
+            "Do not choose among minimum, average, or maximum diameter",
+            "product_length_m",
+            "stateless tool does not recalculate a roll",
+        ):
+            self.assertIn(text, description)
+
 
 if __name__ == "__main__":
     unittest.main()