Harden MCP transport preset routing

mcp_server.py

@@ -57,28 +57,16 @@ def create_server() -> Any:
 
     @server.tool()
     def analyze_transport_capacity(
+        transport_preset: TransportPresetKey,
         roll_diameter_mm: float,
         core_diameter_mm: float,
         roll_width_m: float,
         roll_weight_kg: float,
         product_length_m: float,
-        transport_preset: TransportPresetKey | None = None,
-        length_m: float | None = None,
-        width_m: float | None = None,
-        height_m: float | None = None,
-        max_weight_kg: float | None = None,
-        margin_side_m: float | None = None,
-        margin_ceiling_m: float | None = None,
     ) -> dict[str, Any]:
-        """Analyze transport capacity for calculated rolls. For a chained request, first call get_article and calculate_roll_diameter, then pass every field from its transport_roll_inputs bundle unchanged: roll_diameter_mm, core_diameter_mm, roll_width_m, roll_weight_kg, and product_length_m. Do not choose among minimum, average, or maximum diameter; the bundle contains the browser-equivalent nominal transport diameter. product_length_m is used for reported m², not placement geometry. transport_preset must be one of the listed canonical identifiers: lkw_sattelzug means LKW Sattelzug / semi-trailer and lkw_tandem means LKW Tandem. Alternatively, supply all custom transport dimensions in m and max_weight_kg. This stateless tool does not recalculate a roll; roll_weight_kg is consumed exactly as supplied."""
+        """Use this tool when the user asks how many rolls fit on a known RollCalc transport type. A named transport type is already fully defined by its RollCalc preset: do not ask the user for vehicle dimensions or payload, and do not estimate or invent vehicle data. Use these canonical mappings: LKW-Sattelzug -> lkw_sattelzug; LKW-Tandem -> lkw_tandem; 20ft Container -> container_20ft; 40ft Container -> container_40ft; 40ft High Cube -> container_40ft_hc. If the user asks how many rolls fit on an LKW-Sattelzug, call this tool with transport_preset=\"lkw_sattelzug\". For a chained request, first call get_article and calculate_roll_diameter, then pass every field from its transport_roll_inputs bundle unchanged: roll_diameter_mm, core_diameter_mm, roll_width_m, roll_weight_kg, and product_length_m. Do not choose among minimum, average, or maximum diameter; the bundle contains the browser-equivalent nominal transport diameter. product_length_m is used for reported m², not placement geometry. This stateless tool does not recalculate a roll; roll_weight_kg is consumed exactly as supplied."""
         return analyze_transport_capacity_result(
             transport_preset=transport_preset,
-            length_m=length_m,
-            width_m=width_m,
-            height_m=height_m,
-            max_weight_kg=max_weight_kg,
-            margin_side_m=margin_side_m,
-            margin_ceiling_m=margin_ceiling_m,
             roll_diameter_mm=roll_diameter_mm,
             core_diameter_mm=core_diameter_mm,
             roll_width_m=roll_width_m,

rollcalc_mcp_tools.py

@@ -59,28 +59,16 @@ def calculate_roll_diameter_result(
 
 def analyze_transport_capacity_result(
     *,
-    transport_preset: str | None = None,
-    length_m: float | None = None,
-    width_m: float | None = None,
-    height_m: float | None = None,
-    max_weight_kg: float | None = None,
-    margin_side_m: float | None = None,
-    margin_ceiling_m: float | None = None,
-    roll_diameter_mm: float | None = None,
-    core_diameter_mm: float | None = None,
-    roll_width_m: float | None = None,
-    roll_weight_kg: float | None = None,
-    product_length_m: float | None = None,
+    transport_preset: str,
+    roll_diameter_mm: float,
+    core_diameter_mm: float,
+    roll_width_m: float,
+    roll_weight_kg: float,
+    product_length_m: float,
 ) -> dict[str, Any]:
-    """Map MCP arguments to the shared transport-analysis input shape."""
+    """Map the preset-only MCP contract to the shared transport domain."""
     return analyze_transport({
         "transport_preset": transport_preset,
-        "length_m": length_m,
-        "width_m": width_m,
-        "height_m": height_m,
-        "max_weight_kg": max_weight_kg,
-        "margin_side_m": margin_side_m,
-        "margin_ceiling_m": margin_ceiling_m,
         "roll_diameter_mm": roll_diameter_mm,
         "core_diameter_mm": core_diameter_mm,
         "roll_width_m": roll_width_m,

tests/test_mcp_adapter.py

@@ -1,3 +1,4 @@
+import inspect
 import sys
 import types
 import unittest
@@ -90,33 +91,25 @@ class McpAdapterTests(unittest.TestCase):
         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 (
-            {
-                "transport_preset": "container_20ft",
-                "roll_diameter_mm": 1000.0,
-                "core_diameter_mm": 150.0,
-                "roll_width_m": 2.0,
-                "roll_weight_kg": 1000.0,
-                "product_length_m": 50.0,
-            },
-            {
-                "length_m": 10.0,
-                "width_m": 5.0,
-                "height_m": 5.0,
-                "max_weight_kg": 10000.0,
-                "roll_diameter_mm": 1000.0,
-                "core_diameter_mm": 150.0,
-                "roll_width_m": 1.0,
-                "roll_weight_kg": 1000.0,
-            },
-            {"length_m": 0.0},
-        ):
-            with self.subTest(arguments=arguments):
-                self.assertEqual(
-                    analyze_transport_capacity_result(**arguments),
-                    analyze_transport(arguments),
-                )
+    def test_transport_tool_delegates_to_domain_with_lkw_sattelzug_preset(self):
+        arguments = {
+            "transport_preset": "lkw_sattelzug",
+            "roll_diameter_mm": 1000.0,
+            "core_diameter_mm": 150.0,
+            "roll_width_m": 2.0,
+            "roll_weight_kg": 1000.0,
+            "product_length_m": 50.0,
+        }
+
+        self.assertEqual(
+            analyze_transport_capacity_result(**arguments),
+            analyze_transport(arguments),
+        )
+        result = analyze_transport_capacity_result(**arguments)
+        self.assertEqual(result["status"], "success")
+        self.assertEqual(result["analysis"]["transport_preset"], "lkw_sattelzug")
+        self.assertEqual(result["analysis"]["final_rolls"], 24)
+        self.assertEqual(result["analysis"]["limiting"]["name"], "Weight")
 
     def test_server_registers_exactly_the_three_stdio_poc_tools(self):
         mcp = types.ModuleType("mcp")
@@ -150,12 +143,13 @@ class McpAdapterTests(unittest.TestCase):
         self.assertNotIn("include_roll_weight", roll_schema["properties"])
         preset_schema = transport_schema["properties"]["transport_preset"]
         self.assertEqual(
-            preset_schema["anyOf"][0]["enum"],
+            preset_schema["enum"],
             [preset.key for preset in transport_presets()],
         )
         self.assertEqual(
             transport_schema["required"],
             [
+                "transport_preset",
                 "roll_diameter_mm",
                 "core_diameter_mm",
                 "roll_width_m",
@@ -164,15 +158,39 @@ class McpAdapterTests(unittest.TestCase):
             ],
         )
         for field in transport_schema["required"]:
+            if field == "transport_preset":
+                continue
             self.assertEqual(
                 transport_schema["properties"][field]["type"], "number"
             )
+        for field in (
+            "length_m",
+            "width_m",
+            "height_m",
+            "max_weight_kg",
+            "margin_side_m",
+            "margin_ceiling_m",
+        ):
+            self.assertNotIn(field, transport_schema["properties"])
+            self.assertNotIn(
+                field,
+                inspect.signature(analyze_transport_capacity_result).parameters,
+            )
         description = transport_tool.description
         for text in (
+            "Use this tool when the user asks how many rolls fit on a known RollCalc transport type",
+            "do not ask the user for vehicle dimensions or payload",
+            "LKW-Sattelzug -> lkw_sattelzug",
+            "LKW-Tandem -> lkw_tandem",
+            "20ft Container -> container_20ft",
+            "40ft Container -> container_40ft",
+            "40ft High Cube -> container_40ft_hc",
+            'transport_preset=\"lkw_sattelzug\"',
             "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",
+            "do not estimate or invent",
             "stateless tool does not recalculate a roll",
         ):
             self.assertIn(text, description)