Address PR feedback

Author: stephentoub

src/ModelContextProtocol/Protocol/Messages/ProgressNotification.cs

@@ -42,11 +42,7 @@ public sealed class Converter : JsonConverter<ProgressNotification>
                     switch (propertyName)
                     {
                         case "progressToken":
-                            if (JsonSerializer.Deserialize(ref reader, options.GetTypeInfo(typeof(ProgressToken))) is not ProgressToken token)
-                            {
-                                throw new JsonException("Invalid value for 'progressToken'.");
-                            }
-                            progressToken = token;
+                            progressToken = (ProgressToken)JsonSerializer.Deserialize(ref reader, options.GetTypeInfo(typeof(ProgressToken)))!;
                             break;
 
                         case "progress":

src/ModelContextProtocol/Protocol/Messages/ProgressToken.cs

@@ -36,7 +36,7 @@ public ProgressToken(long value)
 
     /// <inheritdoc />
     public override string? ToString() =>
-        _id is string stringValue ? stringValue :
+        _id is string stringValue ? $"\"{stringValue}\"" :
         _id is long longValue ? longValue.ToString(CultureInfo.InvariantCulture) :
         null;
 

src/ModelContextProtocol/Protocol/Messages/RequestId.cs

@@ -36,7 +36,7 @@ public RequestId(long value)
 
     /// <inheritdoc />
     public override string ToString() =>
-        _id is string stringValue ? stringValue :
+        _id is string stringValue ? $"\"{stringValue}\"" :
         _id is long longValue ? longValue.ToString(CultureInfo.InvariantCulture) :
         string.Empty;
 

tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsToolsTests.cs

@@ -554,7 +554,7 @@ public async Task HandlesIProgressParameter()
         Assert.Equal(10, array.Length);
         for (int i = 0; i < array.Length; i++)
         {
-            Assert.Equal("abc123", array[i].ProgressToken.ToString());
+            Assert.Equal("\"abc123\"", array[i].ProgressToken.ToString());
             Assert.Equal(i, array[i].Progress.Progress);
             Assert.Equal(10, array[i].Progress.Total);
             Assert.Equal($"Progress {i}", array[i].Progress.Message);