fix(registerTool): output validation, title in tools/list, outputSchema emission

- Output schema validation no longer returns parseResult.data (the
  validated structuredContent alone) instead of the full CallToolResult.
- tools/list now includes the tool title field.
- outputSchema is only emitted when the tool defines one (previously
  always emitted a placeholder { type: "object", properties: {} }).
- Remove unused Request/Result imports.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ochafik

src/app.ts

@@ -23,8 +23,6 @@ import {
   ReadResourceRequest,
   ReadResourceResult,
   ReadResourceResultSchema,
-  Request,
-  Result,
   Tool,
   ToolAnnotations,
   ToolListChangedNotification,
@@ -387,7 +385,6 @@ export class App extends ProtocolWithEvents<
               `Invalid output for tool ${name}: ${parseResult.error}`,
             );
           }
-          return parseResult.data;
         }
         return result;
       }) as any,
@@ -433,20 +430,20 @@ export class App extends ProtocolWithEvents<
         .map(([name, tool]) => {
           const result: Tool = {
             name,
+            title: tool.title,
             description: tool.description,
             inputSchema: (tool.inputSchema
               ? z.toJSONSchema(tool.inputSchema as ZodSchema)
               : {
                   type: "object" as const,
                   properties: {},
                 }) as Tool["inputSchema"],
-            outputSchema: (tool.outputSchema
-              ? z.toJSONSchema(tool.outputSchema as ZodSchema)
-              : {
-                  type: "object" as const,
-                  properties: {},
-                }) as Tool["outputSchema"],
           };
+          if (tool.outputSchema) {
+            result.outputSchema = z.toJSONSchema(
+              tool.outputSchema as ZodSchema,
+            ) as Tool["outputSchema"];
+          }
           if (tool.annotations) {
             result.annotations = tool.annotations;
           }