Address PR review feedback

Author: mikekistler

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

@@ -119,7 +119,7 @@ public async ValueTask<IList<McpClientTool>> ListToolsAsync(
             tools ??= new List<McpClientTool>(toolResults.Tools.Count);
             foreach (var tool in toolResults.Tools)
             {
-                tools.Add(new McpClientTool(this, tool, serializerOptions));
+                tools.Add(new McpClientTool(this, tool, options?.JsonSerializerOptions));
             }
 
             cursor = toolResults.NextCursor;
@@ -139,9 +139,6 @@ public async IAsyncEnumerable<McpClientTool> EnumerateToolsAsync(
         RequestOptions? options = null,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
-        var serializerOptions = options?.JsonSerializerOptions ?? McpJsonUtilities.DefaultOptions;
-        serializerOptions.MakeReadOnly();
-
         string? cursor = null;
         do
         {
@@ -154,7 +151,7 @@ public async IAsyncEnumerable<McpClientTool> EnumerateToolsAsync(
 
             foreach (var tool in toolResults.Tools)
             {
-                yield return new McpClientTool(this, tool, serializerOptions);
+                yield return new McpClientTool(this, tool, options?.JsonSerializerOptions);
             }
 
             cursor = toolResults.NextCursor;
@@ -588,12 +585,7 @@ async ValueTask<CallToolResult> SendRequestWithProgressAsync(
                 }).ConfigureAwait(false);
 
             var metaWithProgress = meta is not null ? new JsonObject(meta) : new JsonObject();
-            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")
-                };
+            metaWithProgress["progressToken"] = progressToken.ToString();
 
             return await SendRequestAsync(
                 RequestMethods.ToolsCall,

src/ModelContextProtocol.Core/RequestOptions.cs

@@ -14,6 +14,13 @@ public sealed class RequestOptions
     /// </summary>
     private JsonObject? _meta;
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="RequestOptions"/> class.
+    /// </summary>
+    public RequestOptions()
+    {
+    }
+
     /// <summary>
     /// Optional metadata to include in the request.
     /// When getting, automatically includes the progress token if set.
@@ -52,11 +59,4 @@ public JsonObject? Meta
     /// The progress token for tracking long-running operations.
     /// </summary>
     public ProgressToken? ProgressToken { get; set; }
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="RequestOptions"/> class.
-    /// </summary>
-    public RequestOptions()
-    {
-    }
 }