Apply suggestions from code review

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: stephentoub

src/ModelContextProtocol.Core/Client/McpClient.Methods.cs

@@ -594,7 +594,12 @@ async ValueTask<CallToolResult> SendRequestWithProgressAsync(
                 }).ConfigureAwait(false);
 
             var metaWithProgress = meta is not null ? new JsonObject(meta) : new JsonObject();
-            metaWithProgress["progressToken"] = JsonValue.Create(progressToken.Token as string);
+            metaWithProgress["progressToken"] = progressToken.Token switch
+                {
+                    string s => JsonValue.Create(s),
+                    long l => JsonValue.Create(l),
+                    _ => throw new InvalidOperationException("ProgressToken must be a string or long")
+                };
 
             return await SendRequestAsync(
                 RequestMethods.ToolsCall,

src/ModelContextProtocol.Core/Client/McpClientPrompt.cs

@@ -97,6 +97,6 @@ public async ValueTask<GetPromptResult> GetAsync(
             arguments as IReadOnlyDictionary<string, object?> ??
             arguments?.ToDictionary();
 
-        return await _client.GetPromptAsync(ProtocolPrompt.Name, argDict, new RequestOptions(){JsonSerializerOptions = serializerOptions}, cancellationToken).ConfigureAwait(false);
+        return await _client.GetPromptAsync(ProtocolPrompt.Name, argDict, new RequestOptions() { JsonSerializerOptions = serializerOptions }, cancellationToken).ConfigureAwait(false);
     }
 }

tests/ModelContextProtocol.Tests/Client/McpClientMetaTests.cs

@@ -13,7 +13,7 @@ public McpClientMetaTests(ITestOutputHelper outputHelper)
     {
     }
 
-   protected override void ConfigureServices(ServiceCollection services, IMcpServerBuilder mcpServerBuilder)
+    protected override void ConfigureServices(ServiceCollection services, IMcpServerBuilder mcpServerBuilder)
     {
         services.Configure<McpServerOptions>(o =>
         {