Server instructions added to IMcpClient (#17)

README.MD

@@ -22,7 +22,7 @@ This library aims to provide a clean, specification-compliant implementation of
 - Support for stdio and SSE transports
 - Support for all MCP capabilities: Tool, Resource, Prompt, Sampling, Roots
 - Support for the Completion utility capability
-- Support for pagination and notifications
+- Support for server instructions, pagination and notifications
 - Async/await pattern throughout
 - Comprehensive logging support
 - Compatible with .NET 8.0 and later

samples/anthropic/tools/ToolsConsole/Program.cs

@@ -69,8 +69,16 @@ internal class Program
                 Model = AnthropicModels.Claude35Haiku,
                 Stream = false,
                 Temperature = 1.0m,
-                Tools = anthropicTools
+                Tools = anthropicTools,
+                System = [new SystemMessage("You will be helping the user test MCP server tool call functionality.")]
             };
+
+            // If the server provides instructions, add them as the system prompt
+            if (!string.IsNullOrEmpty(client.ServerInstructions))
+            {
+                parameters.System.Add(new SystemMessage(client.ServerInstructions));
+            }
+
             var res = await antClient.Messages.GetClaudeMessageAsync(parameters);
 
             messages.Add(res.Message);

samples/microsoft.extensions.ai/tools/ToolsConsole/MEAIToolsConsole.csproj

@@ -8,9 +8,12 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="mcpdotnet" Version="0.6.0.1" />
     <PackageReference Include="Microsoft.Extensions.AI" Version="9.1.0-preview.1.25064.3" />
     <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="9.1.0-preview.1.25064.3" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\..\src\mcpdotnet\mcpdotnet.csproj" />
+  </ItemGroup>
+
 </Project>

samples/microsoft.extensions.ai/tools/ToolsConsole/Program.cs

@@ -3,6 +3,7 @@ using McpDotNet.Configuration;
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Logging.Abstractions;
 using OpenAI;
+using OpenAI.Chat;
 using SimpleToolsConsole;
 
 internal class Program
@@ -64,9 +65,22 @@ internal class Program
                 .UseFunctionInvocation()
                 .Build();
 
+            // Create message list
+            IList<Microsoft.Extensions.AI.ChatMessage> messages = new List<Microsoft.Extensions.AI.ChatMessage>();
+            // Add a system message
+            messages.Add(new(ChatRole.System, "You are a helpful assistant, helping us test MCP server functionality."));
+            // If MCP server provides instructions, add them as an additional system message (you could also add it as a content part)
+            if (!string.IsNullOrEmpty(client.ServerInstructions))
+            {
+                messages.Add(new(ChatRole.System, client.ServerInstructions));
+            }
+            // Add a user message
+            messages.Add(new(ChatRole.User, "Please call the echo tool with the string 'Hello MCP!' and give me the response as-is."));
+
+            // Call the chat client
             Console.WriteLine("Asking GPT-4o-mini to call the Echo Tool...");
             var response = chatClient.CompleteStreamingAsync(
-                    "Please call the echo tool with the string 'Hello MCP!' and give me the response as-is.",
+                    messages,
                     new() { Tools = mappedTools });
 
             await foreach (var update in response)

src/mcpdotnet/Client/IMcpClient.cs

@@ -25,6 +25,13 @@ public interface IMcpClient : IAsyncDisposable
     /// </summary>
     Implementation? ServerInfo { get; }
 
+    /// <summary>
+    /// Instructions describing how to use the server and its features.
+    /// This can be used by clients to improve the LLM's understanding of available tools, resources, etc. 
+    /// It can be thought of like a "hint" to the model. For example, this information MAY be added to the system prompt.
+    /// </summary>
+    string? ServerInstructions { get; }
+
     /// <summary>
     /// Gets or sets the handler for server sampling requests.
     /// </summary>

src/mcpdotnet/Client/McpClient.cs

@@ -37,6 +37,9 @@ internal class McpClient : IMcpClient
     /// <inheritdoc/>
     public Implementation? ServerInfo { get; private set; }
 
+    /// <inheritdoc/>
+    public string? ServerInstructions { get; private set; }
+
     /// <summary>
     /// Initializes a new instance of the <see cref="McpClient"/> class.
     /// </summary>
@@ -154,6 +157,7 @@ internal class McpClient : IMcpClient
             _logger.ServerCapabilitiesReceived(_serverConfig.Id, _serverConfig.Name, JsonSerializer.Serialize(initializeResponse.Capabilities), JsonSerializer.Serialize(initializeResponse.ServerInfo));
             ServerCapabilities = initializeResponse.Capabilities;
             ServerInfo = initializeResponse.ServerInfo;
+            ServerInstructions = initializeResponse.Instructions;
 
             // Validate protocol version
             if (initializeResponse.ProtocolVersion != _options.ProtocolVersion)

src/mcpdotnet/mcpdotnet.csproj

@@ -9,7 +9,7 @@
   <PropertyGroup>
     <!-- license and package properties -->
     <PackageId>mcpdotnet</PackageId>
-    <Version>0.8.0.1</Version>
+    <Version>0.9.0.1</Version>
     <Authors>PederHP</Authors>
     <Description>.NET client library for the Model Context Protocol (MCP)</Description>
     <PackageProjectUrl>https://github.com/PederHP/mcpdotnet</PackageProjectUrl>

tests/mcpdotnet.Tests/IntegrationTests.cs

@@ -27,6 +27,22 @@ public class IntegrationTests : IClassFixture<IntegrationTestFixture>
         Assert.NotNull(client);
     }
 
+    [Fact]
+    public async Task Connect_EverythingServer_ShouldProvideServerFields()
+    {
+        // Arrange
+
+        // Act
+        var client = await _fixture.Factory.GetClientAsync("everything");
+
+        // Assert
+        Assert.NotNull(client.ServerCapabilities);
+        Assert.NotNull(client.ServerInfo);
+
+        // Note: Comment the below assertion back when the everything server is updated to provide instructions
+        // Assert.NotNull(client.ServerInstructions);
+    }
+
     [Fact]
     public async Task ListTools_Stdio_EverythingServer()
     {