Add required field for tool input schema for server

example/iostream-client-server/server_iostream.dart

@@ -11,14 +11,17 @@ Future<McpServer> getServer() async {
   mcpServer.tool(
     "calculate",
     description: 'Perform basic arithmetic operations',
-    inputSchemaProperties: {
-      'operation': {
-        'type': 'string',
-        'enum': ['add', 'subtract', 'multiply', 'divide'],
+    toolInputSchema: ToolInputSchema(
+      properties: {
+        'operation': {
+          'type': 'string',
+          'enum': ['add', 'subtract', 'multiply', 'divide'],
+        },
+        'a': {'type': 'number'},
+        'b': {'type': 'number'},
       },
-      'a': {'type': 'number'},
-      'b': {'type': 'number'},
-    },
+      required: ['operation', 'a', 'b'],
+    ),
     callback: ({args, extra}) async {
       final operation = args!['operation'];
       final a = args['a'];

example/server_sse.dart

@@ -11,14 +11,17 @@ Future<void> main() async {
   mcpServer.tool(
     "calculate",
     description: 'Perform basic arithmetic operations',
-    inputSchemaProperties: {
-      'operation': {
-        'type': 'string',
-        'enum': ['add', 'subtract', 'multiply', 'divide'],
+    toolInputSchema: ToolInputSchema(
+      properties: {
+        'operation': {
+          'type': 'string',
+          'enum': ['add', 'subtract', 'multiply', 'divide'],
+        },
+        'a': {'type': 'number'},
+        'b': {'type': 'number'},
       },
-      'a': {'type': 'number'},
-      'b': {'type': 'number'},
-    },
+      required: ['operation', 'a', 'b'],
+    ),
     callback: ({args, extra}) async {
       final operation = args!['operation'];
       final a = args['a'];

example/server_stdio.dart

@@ -15,14 +15,17 @@ void main() async {
   server.tool(
     'calculate',
     description: 'Perform basic arithmetic operations',
-    inputSchemaProperties: {
-      'operation': {
-        'type': 'string',
-        'enum': ['add', 'subtract', 'multiply', 'divide'],
+    toolInputSchema: ToolInputSchema(
+      properties: {
+        'operation': {
+          'type': 'string',
+          'enum': ['add', 'subtract', 'multiply', 'divide'],
+        },
+        'a': {'type': 'number'},
+        'b': {'type': 'number'},
       },
-      'a': {'type': 'number'},
-      'b': {'type': 'number'},
-    },
+      required: ['operation', 'a', 'b'],
+    ),
     callback: ({args, extra}) async {
       final operation = args!['operation'];
       final a = args['a'];

example/streamable_https/server_streamable_https.dart

@@ -67,9 +67,15 @@ McpServer getServer() {
   server.tool(
     'greet',
     description: 'A simple greeting tool',
-    inputSchemaProperties: {
-      'name': {'type': 'string', 'description': 'Name to greet'},
-    },
+    toolInputSchema: ToolInputSchema(
+      properties: {
+        'name': {
+          'type': 'string',
+          'description': 'Name to greet',
+        },
+      },
+      required: ['name'],
+    ),
     callback: ({args, extra}) async {
       final name = args?['name'] as String? ?? 'world';
       return CallToolResult.fromContent(
@@ -85,9 +91,15 @@ McpServer getServer() {
     'multi-greet',
     description:
         'A tool that sends different greetings with delays between them',
-    inputSchemaProperties: {
-      'name': {'type': 'string', 'description': 'Name to greet'},
-    },
+    toolInputSchema: ToolInputSchema(
+      properties: {
+        'name': {
+          'type': 'string',
+          'description': 'Name to greet',
+        },
+      },
+      required: [],
+    ),
     annotations: ToolAnnotations(
       title: 'Multiple Greeting Tool',
       readOnlyHint: true,
@@ -162,18 +174,20 @@ McpServer getServer() {
     'start-notification-stream',
     description:
         'Starts sending periodic notifications for testing resumability',
-    inputSchemaProperties: {
-      'interval': {
-        'type': 'number',
-        'description': 'Interval in milliseconds between notifications',
-        'default': 100,
-      },
-      'count': {
-        'type': 'number',
-        'description': 'Number of notifications to send (0 for 100)',
-        'default': 50,
+    toolInputSchema: ToolInputSchema(
+      properties: {
+        'interval': {
+          'type': 'number',
+          'description': 'Interval in milliseconds between notifications',
+          'default': 100,
+        },
+        'count': {
+          'type': 'number',
+          'description': 'Number of notifications to send (0 for 100)',
+          'default': 50,
+        },
       },
-    },
+    ),
     callback: ({args, extra}) async {
       final interval = args?['interval'] as num? ?? 100;
       final count = args?['count'] as num? ?? 50;

example/weather.dart

@@ -53,12 +53,15 @@ void main() async {
   server.tool(
     "get-alerts",
     description: "Get weather alerts for a state",
-    inputSchemaProperties: {
-      "state": {
-        "type": "string",
-        "description": "Two-letter state code (e.g. CA, NY)",
+    toolInputSchema: ToolInputSchema(
+      properties: {
+        "state": {
+          "type": "string",
+          "description": "Two-letter state code (e.g. CA, NY)",
+        },
       },
-    },
+      required: ["state"],
+    ),
     callback: ({args, extra}) async {
       final state = (args?['state'] as String?)?.toUpperCase();
       if (state == null || state.length != 2) {
@@ -98,13 +101,19 @@ void main() async {
   server.tool(
     "get-forecast",
     description: "Get weather forecast for a location",
-    inputSchemaProperties: {
-      "latitude": {"type": "number", "description": "Latitude of the location"},
-      "longitude": {
-        "type": "number",
-        "description": "Longitude of the location",
+    toolInputSchema: ToolInputSchema(
+      properties: {
+        "latitude": {
+          "type": "number",
+          "description": "Latitude of the location",
+        },
+        "longitude": {
+          "type": "number",
+          "description": "Longitude of the location",
+        },
       },
-    },
+      required: ["latitude", "longitude"],
+    ),
     callback: ({args, extra}) async {
       final latitude = args?['latitude'] as num?;
       final longitude = args?['longitude'] as num?;

lib/src/server/mcp.dart

@@ -82,15 +82,15 @@ class ResourceTemplateRegistration {
 
 class _RegisteredTool {
   final String? description;
-  final Map<String, dynamic>? inputSchemaProperties;
-  final Map<String, dynamic>? outputSchemaProperties;
+  final ToolInputSchema? toolInputSchema;
+  final ToolOutputSchema? toolOutputSchema;
   final ToolAnnotations? annotations;
   final ToolCallback callback;
 
   const _RegisteredTool({
     this.description,
-    this.inputSchemaProperties,
-    this.outputSchemaProperties,
+    this.toolInputSchema,
+    this.toolOutputSchema,
     this.annotations,
     required this.callback,
   });
@@ -99,11 +99,9 @@ class _RegisteredTool {
     return Tool(
       name: name,
       description: description,
-      inputSchema: ToolInputSchema(properties: inputSchemaProperties),
+      inputSchema: toolInputSchema ?? ToolInputSchema(),
       // Do not include output schema in the payload if it isn't defined
-      outputSchema: outputSchemaProperties != null
-          ? ToolOutputSchema(properties: outputSchemaProperties)
-          : null,
+      outputSchema: toolOutputSchema,
       annotations: annotations,
     );
   }
@@ -567,7 +565,11 @@ class McpServer {
   void tool(
     String name, {
     String? description,
+    ToolInputSchema? toolInputSchema,
+    ToolOutputSchema? toolOutputSchema,
+    @Deprecated('Use toolInputSchema instead')
     Map<String, dynamic>? inputSchemaProperties,
+    @Deprecated('Use toolOutputSchema instead')
     Map<String, dynamic>? outputSchemaProperties,
     ToolAnnotations? annotations,
     required ToolCallback callback,
@@ -577,8 +579,14 @@ class McpServer {
     }
     _registeredTools[name] = _RegisteredTool(
       description: description,
-      inputSchemaProperties: inputSchemaProperties,
-      outputSchemaProperties: outputSchemaProperties,
+      toolInputSchema: toolInputSchema ??
+          (inputSchemaProperties != null
+              ? ToolInputSchema(properties: inputSchemaProperties)
+              : null),
+      toolOutputSchema: toolOutputSchema ??
+          (outputSchemaProperties != null
+              ? ToolOutputSchema(properties: outputSchemaProperties)
+              : null),
       annotations: annotations,
       callback: callback,
     );