fix: address PR review feedback

- Fix defineTool signature in TS scenario and docs (name, config)
- Remove unused System.Text.Json import from C# scenario

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: MackinnonBuck

docs/features/custom-agents.md

@@ -775,8 +775,7 @@ This is useful when:
 import { CopilotClient, defineTool, approveAll } from "@github/copilot-sdk";
 import { z } from "zod";
 
-const heavyContextTool = defineTool({
-    name: "analyze-codebase",
+const heavyContextTool = defineTool("analyze-codebase", {
     description: "Performs deep analysis of the codebase, generating extensive context",
     parameters: z.object({ query: z.string() }),
     handler: async ({ query }) => {

test/scenarios/tools/custom-agents/csharp/Program.cs

@@ -1,4 +1,3 @@
-using System.Text.Json;
 using GitHub.Copilot.SDK;
 using Microsoft.Extensions.AI;
 

test/scenarios/tools/custom-agents/typescript/src/index.ts

@@ -1,8 +1,7 @@
 import { CopilotClient, defineTool } from "@github/copilot-sdk";
 import { z } from "zod";
 
-const analyzeCodebase = defineTool({
-    name: "analyze-codebase",
+const analyzeCodebase = defineTool("analyze-codebase", {
     description: "Performs deep analysis of the codebase, generating extensive context",
     parameters: z.object({ query: z.string().describe("The analysis query") }),
     handler: async ({ query }) => {