diff --git a/README.md b/README.md
index a291c3d..f9fe5bb 100644
--- a/README.md
+++ b/README.md
@@ -157,7 +157,10 @@ Tool calling semantics:
   weight, and the domain returns the governing constraint(s), unrounded.
   Core and width incompatibility cannot be corrected by shortening and is
   returned structurally. No manufacturing increment, core/packaging/gross
-  weight, or conditional production rule is applied in V1.1.
+  weight, or conditional production rule is applied in V1.1. Its successful
+  MCP response is a compact projection: machine identity, configured maximum
+  diameter/material-weight limits, production maxima, material weights, and
+  warnings. Flask and other domain consumers retain the full diagnostic result.
 - `calculate_product_length` calculates required roll length from a target outer
   diameter, core diameter, and material thickness. Its optional thickness
   stddev returns minimum/average/maximum length ranges; optional width and area
diff --git a/rollcalc_mcp_tools.py b/rollcalc_mcp_tools.py
index 9dcf5dc..c3e4a34 100644
--- a/rollcalc_mcp_tools.py
+++ b/rollcalc_mcp_tools.py
@@ -69,8 +69,8 @@ def calculate_machine_max_product_length_result(
     product_width_m: float | None = None,
     area_weight_g_m2: float | None = None,
 ) -> dict[str, Any]:
-    """Delegate machine-aware maximum product length to the shared domain."""
-    return calculate_machine_max_product_length(
+    """Return the compact MCP view of the machine-aware domain calculation."""
+    result = calculate_machine_max_product_length(
         machine=machine,
         core_diameter_mm=core_diameter_mm,
         thickness_mm=thickness_mm,
@@ -78,6 +78,35 @@ def calculate_machine_max_product_length_result(
         product_width_m=product_width_m,
         area_weight_g_m2=area_weight_g_m2,
     )
+    return project_machine_max_product_length_result(result)
+
+
+def project_machine_max_product_length_result(result: dict[str, Any]) -> dict[str, Any]:
+    """Project successful maximum-length results for MCP without diagnostics.
+
+    The shared domain result deliberately contains detailed verification reports.
+    They remain available to Flask and other consumers, but duplicate machine
+    metadata and checks are unnecessary in the MCP response.
+    """
+    if result.get("status") != "success":
+        return result
+
+    machine = result["machine"]
+    constraints = machine["constraints"]
+    return {
+        "status": result["status"],
+        "machine": {"id": machine["id"], "name": machine["name"]},
+        "weight_scope": result["weight_scope"],
+        "machine_limits": {
+            "maximum_roll_diameter_mm": constraints["roll_diameter_mm"]["maximum"]
+            if constraints["roll_diameter_mm"] is not None else None,
+            "maximum_material_roll_weight_kg": constraints["roll_weight_kg"]["maximum"]
+            if constraints["roll_weight_kg"] is not None else None,
+        },
+        "production_maximums": result["production_maximums"],
+        "material_weights_kg": result["material_weights_kg"],
+        "warnings": result["warnings"],
+    }
 
 
 def calculate_material_weight_result(
diff --git a/tests/test_calculation_api.py b/tests/test_calculation_api.py
index 9e01d30..960f5fb 100644
--- a/tests/test_calculation_api.py
+++ b/tests/test_calculation_api.py
@@ -5,6 +5,7 @@ import unittest
 from unittest.mock import patch
 
 import app as rollcalc_app
+from machine_constraints import calculate_machine_max_product_length
 
 
 class CalculationApiTests(unittest.TestCase):
@@ -140,21 +141,24 @@ class CalculationApiTests(unittest.TestCase):
         self.assertEqual(result["warning_constraints"], ["roll_diameter_mm"])
 
     def test_machine_maximum_length_endpoint_is_authenticated_and_structured(self):
+        payload = {
+            "machine": "K7",
+            "core_diameter_mm": 133,
+            "thickness_mm": 4.311611,
+            "thickness_stddev_mm": 0.249999,
+            "product_width_m": 6,
+            "area_weight_g_m2": 495.395833,
+        }
         response = self.client.post(
             "/api/calculations/machine-max-product-length",
-            json={
-                "machine": "K7",
-                "core_diameter_mm": 133,
-                "thickness_mm": 4.311611,
-                "thickness_stddev_mm": 0.249999,
-                "product_width_m": 6,
-                "area_weight_g_m2": 495.395833,
-            },
+            json=payload,
             headers=self.headers,
         )
         result = response.get_json()
         self.assertEqual(response.status_code, 200)
         self.assertEqual(result["status"], "success")
+        self.assertEqual(result, calculate_machine_max_product_length(**payload))
+        self.assertIn("final_feasibility", result)
         self.assertEqual(
             result["production_maximums"]["nominal_governing_constraints"],
             ["roll_diameter_nominal"],
diff --git a/tests/test_mcp_adapter.py b/tests/test_mcp_adapter.py
index df2616d..974219c 100644
--- a/tests/test_mcp_adapter.py
+++ b/tests/test_mcp_adapter.py
@@ -1,3 +1,4 @@
+import copy
 import inspect
 import sys
 import types
@@ -21,6 +22,7 @@ from rollcalc_mcp_tools import (
     calculate_roll_diameter_result,
     get_article_result,
     get_machine_result,
+    project_machine_max_product_length_result,
     search_articles_result,
 )
 from machine_constraints import (
@@ -103,7 +105,7 @@ class McpAdapterTests(unittest.TestCase):
             "feasible_with_warnings",
         )
 
-    def test_machine_maximum_length_adapter_delegates_to_shared_domain(self):
+    def test_machine_maximum_length_adapter_projects_success_without_mutating_domain(self):
         arguments = {
             "machine": "K7",
             "core_diameter_mm": 133.0,
@@ -112,10 +114,79 @@ class McpAdapterTests(unittest.TestCase):
             "product_width_m": 6.0,
             "area_weight_g_m2": 495.395833,
         }
+        domain_result = calculate_machine_max_product_length(**arguments)
+        domain_before_projection = copy.deepcopy(domain_result)
+
+        result = project_machine_max_product_length_result(domain_result)
+
+        self.assertEqual(domain_result, domain_before_projection)
+        self.assertIn("final_feasibility", domain_result)
+        self.assertNotIn("final_feasibility", result)
         self.assertEqual(
-            calculate_machine_max_product_length_result(**arguments),
-            calculate_machine_max_product_length(**arguments),
+            calculate_machine_max_product_length_result(**arguments), result
         )
+        self.assertEqual(result["machine"], {"id": "k7", "name": "K7"})
+        self.assertEqual(result["weight_scope"], "material_only")
+        self.assertEqual(result["machine_limits"], {
+            "maximum_roll_diameter_mm": 1100.0,
+            "maximum_material_roll_weight_kg": 700.0,
+        })
+        self.assertEqual(result["production_maximums"], {
+            "nominal_length_m": 217.1900177447768,
+            "nominal_governing_constraints": ["roll_diameter_nominal"],
+            "conservative_length_m": 194.62073281485985,
+            "conservative_governing_constraints": ["roll_diameter_conservative"],
+        })
+        self.assertEqual(result["material_weights_kg"], {
+            "at_nominal_production_maximum": 645.570178559751,
+            "at_conservative_production_maximum": 578.4858003113276,
+        })
+        self.assertEqual(result["warnings"], {"nominal": ["roll_diameter_mm"]})
+
+    def test_machine_maximum_length_adapter_preserves_non_success_diagnostics(self):
+        base = {
+            "machine": "K7",
+            "core_diameter_mm": 133.0,
+            "thickness_mm": 4.311611,
+            "thickness_stddev_mm": 0.249999,
+            "product_width_m": 6.0,
+            "area_weight_g_m2": 495.395833,
+        }
+        for changes, status in (
+            ({"core_diameter_mm": 194.0}, "incompatible"),
+            ({"product_width_m": 3.0}, "incompatible"),
+            (
+                {"product_width_m": None, "area_weight_g_m2": None},
+                "needs_clarification",
+            ),
+            ({"thickness_mm": -1.0}, "invalid_parameter"),
+            ({"machine": "not configured"}, "machine_not_found"),
+        ):
+            with self.subTest(changes=changes):
+                arguments = {**base, **changes}
+                domain_result = calculate_machine_max_product_length(**arguments)
+                adapter_result = calculate_machine_max_product_length_result(**arguments)
+                self.assertEqual(adapter_result, domain_result)
+                self.assertEqual(adapter_result["status"], status)
+
+        missing = calculate_machine_max_product_length_result(
+            **{**base, "product_width_m": None, "area_weight_g_m2": None}
+        )
+        self.assertEqual(
+            missing["missing_required_inputs"],
+            ["product_width_m", "area_weight_g_m2"],
+        )
+        core = calculate_machine_max_product_length_result(
+            **{**base, "core_diameter_mm": 194.0}
+        )
+        self.assertEqual(
+            core["failed_compatibility_constraints"],
+            ["allowed_core_diameters_mm"],
+        )
+        width = calculate_machine_max_product_length_result(
+            **{**base, "product_width_m": 3.0}
+        )
+        self.assertEqual(width["failed_compatibility_constraints"], ["product_width_m"])
 
     def test_material_weight_adapter_delegates_without_a_core_diameter(self):
         arguments = {