feat: Add output schema support to MCP tools (#153)

tests/Inspector/Stdio/snapshots/StdioCustomDependenciesTest-tools_call-add_task.json

@@ -5,5 +5,12 @@
       "text": "{\n    \"id\": 4,\n    \"userId\": \"alice\",\n    \"description\": \"Complete the project documentation\",\n    \"completed\": false,\n    \"createdAt\": \"2025-01-01T00:00:00+00:00\"\n}"
     }
   ],
+  "structuredContent": {
+    "id": 4,
+    "userId": "alice",
+    "description": "Complete the project documentation",
+    "completed": false,
+    "createdAt": "2025-01-01T00:00:00+00:00"
+  },
   "isError": false
-}
+}

tests/Inspector/Stdio/snapshots/StdioCustomDependenciesTest-tools_call-complete_task.json

@@ -5,5 +5,9 @@
       "text": "{\n    \"success\": true,\n    \"message\": \"Task 1 completed.\"\n}"
     }
   ],
+  "structuredContent": {
+    "success": true,
+    "message": "Task 1 completed."
+  },
   "isError": false
 }

tests/Inspector/Stdio/snapshots/StdioDiscoveryCalculatorTest-tools_call-update_setting.json

@@ -5,5 +5,9 @@
       "text": "{\n    \"success\": true,\n    \"message\": \"Precision updated to 3.\"\n}"
     }
   ],
+  "structuredContent": {
+    "success": true,
+    "message": "Precision updated to 3."
+  },
   "isError": false
 }

tests/Inspector/Stdio/snapshots/StdioDiscoveryCalculatorTest-tools_call.json

@@ -5,5 +5,8 @@
       "text": "19.8"
     }
   ],
-  "isError": false
+  "isError": false,
+  "structuredContent": {
+    "result": 19.8
+  }
 }

tests/Inspector/Stdio/snapshots/StdioEnvVariablesTest-tools_call-process_data_debug.json

@@ -5,5 +5,10 @@
       "text": "{\n    \"mode\": \"debug\",\n    \"processed_input\": \"DEBUG TEST\",\n    \"message\": \"Processed in DEBUG mode.\"\n}"
     }
   ],
-  "isError": false
+  "isError": false,
+  "structuredContent": {
+    "mode": "debug",
+    "processed_input": "DEBUG TEST",
+    "message": "Processed in DEBUG mode."
+  }
 }

tests/Inspector/Stdio/snapshots/StdioEnvVariablesTest-tools_call-process_data_default.json

@@ -5,5 +5,10 @@
       "text": "{\n    \"mode\": \"default\",\n    \"original_input\": \"test data\",\n    \"message\": \"Processed in default mode (APP_MODE not recognized or not set).\"\n}"
     }
   ],
-  "isError": false
+  "isError": false,
+  "structuredContent": {
+    "mode": "default",
+    "original_input": "test data",
+    "message": "Processed in default mode (APP_MODE not recognized or not set)."
+  }
 }

tests/Inspector/Stdio/snapshots/StdioEnvVariablesTest-tools_call-process_data_production.json

@@ -5,5 +5,10 @@
       "text": "{\n    \"mode\": \"production\",\n    \"processed_input_length\": 15,\n    \"message\": \"Processed in PRODUCTION mode (summary only).\"\n}"
     }
   ],
-  "isError": false
+  "isError": false,
+  "structuredContent": {
+    "mode": "production",
+    "processed_input_length": 15,
+    "message": "Processed in PRODUCTION mode (summary only)."
+  }
 }

tests/Inspector/Stdio/snapshots/StdioEnvVariablesTest-tools_list.json

@@ -14,6 +14,31 @@
         "required": [
           "input"
         ]
+      },
+      "outputSchema": {
+        "type": "object",
+        "properties": {
+          "mode": {
+            "type": "string",
+            "description": "The processing mode used"
+          },
+          "processed_input": {
+            "type": "string",
+            "description": "The processed input data"
+          },
+          "original_input": {
+            "type": "string",
+            "description": "The original input data (only in default mode)"
+          },
+          "message": {
+            "type": "string",
+            "description": "A descriptive message about the processing"
+          }
+        },
+        "required": [
+          "mode",
+          "message"
+        ]
       }
     }
   ]