Address feedback, more cleanup, fix NAOT test failure

Author: stephentoub

samples/EverythingServer/Tools/AnnotatedMessageTool.cs

@@ -19,17 +19,17 @@ public static IEnumerable<ContentBlock> AnnotatedMessage(MessageType messageType
     {
         List<ContentBlock> contents = messageType switch
         {
-            MessageType.Error => [new TextContentBlock()
+            MessageType.Error => [new TextContentBlock
             {
                 Text = "Error: Operation failed",
                 Annotations = new() { Audience = [Role.User, Role.Assistant], Priority = 1.0f }
             }],
-            MessageType.Success => [new TextContentBlock()
+            MessageType.Success => [new TextContentBlock
             {
                 Text = "Operation completed successfully",
                 Annotations = new() { Audience = [Role.User], Priority = 0.7f }
             }],
-            MessageType.Debug => [new TextContentBlock()
+            MessageType.Debug => [new TextContentBlock
             {
                 Text = "Debug: Cache hit ratio 0.95, latency 150ms",
                 Annotations = new() { Audience = [Role.Assistant], Priority = 0.3f }

samples/EverythingServer/Tools/SampleLlmTool.cs

@@ -27,7 +27,7 @@ private static CreateMessageRequestParams CreateRequestSamplingParams(string con
             Messages = [new SamplingMessage()
                 {
                     Role = Role.User,
-                    Content = new TextContentBlock() { Text = $"Resource {uri} context: {context}" },
+                    Content = new TextContentBlock { Text = $"Resource {uri} context: {context}" },
                 }],
             SystemPrompt = "You are a helpful test server.",
             MaxTokens = maxTokens,

samples/QuickstartWeatherServer/Program.cs

@@ -17,7 +17,7 @@
 
 builder.Services.AddSingleton(_ =>
 {
-    var client = new HttpClient() { BaseAddress = new Uri("https://api.weather.gov") };
+    var client = new HttpClient { BaseAddress = new Uri("https://api.weather.gov") };
     client.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("weather-tool", "1.0"));
     return client;
 });

samples/TestServerWithHosting/Tools/SampleLlmTool.cs

@@ -30,7 +30,7 @@ private static CreateMessageRequestParams CreateRequestSamplingParams(string con
             Messages = [new SamplingMessage()
                 {
                     Role = Role.User,
-                    Content = new TextContentBlock() { Text = $"Resource {uri} context: {context}" },
+                    Content = new TextContentBlock { Text = $"Resource {uri} context: {context}" },
                 }],
             SystemPrompt = "You are a helpful test server.",
             MaxTokens = maxTokens,

src/ModelContextProtocol.Core/AIContentExtensions.cs

@@ -183,7 +183,7 @@ public static IList<AIContent> ToAIContents(this IEnumerable<ResourceContents> c
     internal static ContentBlock ToContent(this AIContent content) =>
         content switch
         {
-            TextContent textContent => new TextContentBlock()
+            TextContent textContent => new TextContentBlock
             {
                 Text = textContent.Text,
             },
@@ -209,7 +209,7 @@ internal static ContentBlock ToContent(this AIContent content) =>
                 }
             },
 
-            _ => new TextContentBlock()
+            _ => new TextContentBlock
             {
                 Text = JsonSerializer.Serialize(content, McpJsonUtilities.DefaultOptions.GetTypeInfo(typeof(object))),
             }

src/ModelContextProtocol.Core/Client/McpClientExtensions.cs

@@ -957,7 +957,7 @@ internal static CreateMessageResult ToCreateMessageResult(this ChatResponse chat
 
         return new()
         {
-            Content = content ?? new TextContentBlock() { Text = lastMessage?.Text ?? string.Empty },
+            Content = content ?? new TextContentBlock { Text = lastMessage?.Text ?? string.Empty },
             Model = chatResponse.ModelId ?? "unknown",
             Role = lastMessage?.Role == ChatRole.User ? Role.User : Role.Assistant,
             StopReason = chatResponse.FinishReason == ChatFinishReason.Length ? "maxTokens" : "endTurn",

src/ModelContextProtocol.Core/Client/McpClientOptions.cs

@@ -9,7 +9,7 @@ namespace ModelContextProtocol.Client;
 /// These options are typically passed to <see cref="McpClientFactory.CreateAsync"/> when creating a client.
 /// They define client capabilities, protocol version, and other client-specific settings.
 /// </remarks>
-public class McpClientOptions
+public sealed class McpClientOptions
 {
     /// <summary>
     /// Gets or sets information about this client implementation, including its name and version.

src/ModelContextProtocol.Core/Client/SseClientTransportOptions.cs

@@ -3,7 +3,7 @@ namespace ModelContextProtocol.Client;
 /// <summary>
 /// Provides options for configuring <see cref="SseClientTransport"/> instances.
 /// </summary>
-public class SseClientTransportOptions
+public sealed class SseClientTransportOptions
 {
     /// <summary>
     /// Gets or sets the base address of the server for SSE connections.
@@ -69,5 +69,5 @@ public required Uri Endpoint
     /// <remarks>
     /// Use this property to specify custom HTTP headers that should be sent with each request to the server.
     /// </remarks>
-    public Dictionary<string, string>? AdditionalHeaders { get; set; }
+    public IDictionary<string, string>? AdditionalHeaders { get; set; }
 }

src/ModelContextProtocol.Core/Client/StdioClientTransportOptions.cs

@@ -3,7 +3,7 @@ namespace ModelContextProtocol.Client;
 /// <summary>
 /// Provides options for configuring <see cref="StdioClientTransport"/> instances.
 /// </summary>
-public class StdioClientTransportOptions
+public sealed class StdioClientTransportOptions
 {
     /// <summary>
     /// Gets or sets the command to execute to start the server process.
@@ -53,7 +53,7 @@ public required string Command
     /// That includes removing the variables for any of this collection's entries with a null value.
     /// </para>
     /// </remarks>
-    public Dictionary<string, string?>? EnvironmentVariables { get; set; }
+    public IDictionary<string, string?>? EnvironmentVariables { get; set; }
 
     /// <summary>
     /// Gets or sets the timeout to wait for the server to shut down gracefully.

src/ModelContextProtocol.Core/Client/StreamableHttpClientSessionTransport.cs

@@ -244,7 +244,7 @@ private void LogJsonException(JsonException ex, string data)
         }
     }
 
-    internal static void CopyAdditionalHeaders(HttpRequestHeaders headers, Dictionary<string, string>? additionalHeaders, string? sessionId = null)
+    internal static void CopyAdditionalHeaders(HttpRequestHeaders headers, IDictionary<string, string>? additionalHeaders, string? sessionId = null)
     {
         if (sessionId is not null)
         {