.Net: Update MCP nuget package (#11288)

### Motivation, Context and Description

Update the MCP samples to use the latest MCP nuget package.

**Contributes to**:
#11199

Author: SergeyMenshykh

dotnet/Directory.Packages.props

@@ -29,7 +29,7 @@
     <PackageVersion Include="EntityFramework" Version="6.5.1" />
     <PackageVersion Include="FastBertTokenizer" Version="1.0.28" />
     <PackageVersion Include="Google.Apis.Auth" Version="1.69.0" />
-    <PackageVersion Include="ModelContextProtocol" Version="0.1.0-preview.1.25171.12" />
+    <PackageVersion Include="ModelContextProtocol" Version="0.1.0-preview.4" />
     <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.13" />
     <PackageVersion Include="Microsoft.AspNetCore.OpenApi" Version="8.0.14" />
     <PackageVersion Include="Microsoft.ML.Tokenizers.Data.Cl100kBase" Version="1.0.1" />

dotnet/samples/Demos/ModelContextProtocolClientServer/MCPClient/Program.cs

@@ -9,8 +9,8 @@
 using Microsoft.Extensions.Logging;
 using Microsoft.SemanticKernel;
 using Microsoft.SemanticKernel.Connectors.OpenAI;
+using ModelContextProtocol;
 using ModelContextProtocol.Client;
-using ModelContextProtocol.Configuration;
 using ModelContextProtocol.Protocol.Transport;
 
 namespace MCPClient;
@@ -52,7 +52,7 @@ public static async Task Main(string[] args)
 
         // Retrieve and display the list of tools available on the MCP server
         Console.WriteLine("Available MCP tools:");
-        var tools = await mcpClient.GetAIFunctionsAsync().ConfigureAwait(false);
+        var tools = await mcpClient.ListToolsAsync().ConfigureAwait(false);
         foreach (var tool in tools)
         {
             Console.WriteLine($"{tool.Name}: {tool.Description}");

dotnet/samples/Demos/ModelContextProtocolClientServer/MCPServer/Extensions/McpServerBuilderExtensions.cs

@@ -0,0 +1,31 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using Microsoft.SemanticKernel;
+using ModelContextProtocol.Server;
+
+namespace MCPServer;
+
+/// <summary>
+/// Extension methods for <see cref="IMcpServerBuilder"/>.
+/// </summary>
+public static class McpServerBuilderExtensions
+{
+    /// <summary>
+    /// Adds all functions of the kernel plugins as tools to the server.
+    /// </summary>
+    /// <param name="builder">The builder instance.</param>
+    /// <param name="plugins">The kernel plugins to add as tools to the server.</param>
+    /// <returns>The builder instance.</returns>
+    public static IMcpServerBuilder WithTools(this IMcpServerBuilder builder, KernelPluginCollection plugins)
+    {
+        foreach (var plugin in plugins)
+        {
+            foreach (var function in plugin)
+            {
+                builder.Services.AddSingleton(services => McpServerTool.Create(function.AsAIFunction()));
+            }
+        }
+
+        return builder;
+    }
+}

dotnet/samples/Demos/ModelContextProtocolClientServer/MCPServer/Program.cs

@@ -1,8 +1,8 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using MCPServer;
 using MCPServer.Tools;
 using Microsoft.SemanticKernel;
-using ModelContextProtocol;
 
 // Create a kernel builder and add plugins
 IKernelBuilder kernelBuilder = Kernel.CreateBuilder();
@@ -16,6 +16,6 @@
 builder.Services
     .AddMcpServer()
     .WithStdioServerTransport()
-    // Add kernel functions to the MCP server as MCP tools
-    .WithTools(kernel.Plugins.SelectMany(p => p.Select(f => f.AsAIFunction())));
+    // Add all functions from the kernel plugins to the MCP server as tools
+    .WithTools(kernel.Plugins);
 await builder.Build().RunAsync();

dotnet/samples/Demos/ModelContextProtocolPlugin/Program.cs

@@ -34,7 +34,7 @@
     new() { ClientInfo = new() { Name = "GitHub", Version = "1.0.0" } }).ConfigureAwait(false);
 
 // Retrieve the list of tools available on the GitHub server
-var tools = await mcpClient.GetAIFunctionsAsync().ConfigureAwait(false);
+var tools = await mcpClient.ListToolsAsync().ConfigureAwait(false);
 foreach (var tool in tools)
 {
     Console.WriteLine($"{tool.Name}: {tool.Description}");