Remove default value extraction code and linker annotations per feedback

Co-authored-by: eiriktsarpalis <[email protected]>

Author: Copilot

src/ModelContextProtocol.Core/Server/McpServer.Methods.cs

@@ -2,9 +2,7 @@
 using Microsoft.Extensions.Logging;
 using ModelContextProtocol.Protocol;
 using System.Collections.Concurrent;
-using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
-using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Text;
 using System.Text.Json;
@@ -259,9 +257,9 @@ public async ValueTask<ElicitResult<T>> ElicitAsync<T>(
         var dict = s_elicitResultSchemaCache.GetValue(serializerOptions, _ => new());
 
 #if NET
-        var schema = dict.GetOrAdd(typeof(T), static (t, s) => BuildRequestSchemaHelper(t, s), serializerOptions);
+        var schema = dict.GetOrAdd(typeof(T), static (t, s) => BuildRequestSchema(t, s), serializerOptions);
 #else
-        var schema = dict.GetOrAdd(typeof(T), type => BuildRequestSchemaHelper(type, serializerOptions));
+        var schema = dict.GetOrAdd(typeof(T), type => BuildRequestSchema(type, serializerOptions));
 #endif
 
         var request = new ElicitRequestParams
@@ -287,21 +285,14 @@ public async ValueTask<ElicitResult<T>> ElicitAsync<T>(
         return new ElicitResult<T> { Action = raw.Action, Content = typed };
     }
 
-    /// <summary>
-    /// Helper method for BuildRequestSchema that can be called from lambdas without annotation issues.
-    /// </summary>
-    [UnconditionalSuppressMessage("Trimming", "IL2067", Justification = "Type T is preserved via JsonTypeInfo")]
-    private static ElicitRequestParams.RequestSchema BuildRequestSchemaHelper(Type type, JsonSerializerOptions serializerOptions)
-        => BuildRequestSchema(type, serializerOptions);
-
     /// <summary>
     /// Builds a request schema for elicitation based on the public serializable properties of <paramref name="type"/>.
     /// </summary>
     /// <param name="type">The type of the schema being built.</param>
     /// <param name="serializerOptions">The serializer options to use.</param>
     /// <returns>The built request schema.</returns>
     /// <exception cref="McpProtocolException"></exception>
-    private static ElicitRequestParams.RequestSchema BuildRequestSchema([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicProperties)] Type type, JsonSerializerOptions serializerOptions)
+    private static ElicitRequestParams.RequestSchema BuildRequestSchema(Type type, JsonSerializerOptions serializerOptions)
     {
         var schema = new ElicitRequestParams.RequestSchema();
         var props = schema.Properties;
@@ -316,47 +307,11 @@ private static ElicitRequestParams.RequestSchema BuildRequestSchema([Dynamically
         foreach (JsonPropertyInfo pi in typeInfo.Properties)
         {
             var def = CreatePrimitiveSchema(pi.PropertyType, serializerOptions);
-            
-            // Extract default value from DefaultValueAttribute if present
-            var propInfo = type.GetProperty(pi.Name);
-            if (propInfo != null)
-            {
-                var defaultValueAttr = propInfo.GetCustomAttribute<System.ComponentModel.DefaultValueAttribute>();
-                if (defaultValueAttr?.Value != null)
-                {
-                    SetDefaultValue(def, defaultValueAttr.Value);
-                }
-            }
-            
             props[pi.Name] = def;
         }
 
         return schema;
     }
-    
-    /// <summary>
-    /// Sets the default value on a primitive schema definition based on the value type.
-    /// </summary>
-    /// <param name="schema">The schema to set the default value on.</param>
-    /// <param name="value">The default value.</param>
-    private static void SetDefaultValue(ElicitRequestParams.PrimitiveSchemaDefinition schema, object value)
-    {
-        switch (schema)
-        {
-            case ElicitRequestParams.StringSchema stringSchema:
-                stringSchema.Default = value?.ToString();
-                break;
-            case ElicitRequestParams.NumberSchema numberSchema:
-                numberSchema.Default = Convert.ToDouble(value);
-                break;
-            case ElicitRequestParams.BooleanSchema booleanSchema:
-                booleanSchema.Default = Convert.ToBoolean(value);
-                break;
-            case ElicitRequestParams.EnumSchema enumSchema:
-                enumSchema.Default = value?.ToString();
-                break;
-        }
-    }
 
     /// <summary>
     /// Creates a primitive schema definition for the specified type, if supported.

tests/ModelContextProtocol.Tests/Protocol/ElicitationTypedTests.cs

@@ -86,19 +86,6 @@ await request.Server.ElicitAsync<string>(
                     Content = [new TextContentBlock { Text = "unexpected" }],
                 };
             }
-            else if (request.Params!.Name == "TestElicitationWithDefaults")
-            {
-                var result = await request.Server.ElicitAsync<FormWithDefaults>(
-                    message: "Please provide information.",
-                    serializerOptions: ElicitationDefaultsJsonContext.Default.Options,
-                    cancellationToken: CancellationToken.None);
-
-                // The test will validate the schema in the client handler
-                return new CallToolResult
-                {
-                    Content = [new TextContentBlock { Text = "success" }],
-                };
-            }
             else
             {
                 Assert.Fail($"Unexpected tool name: {request.Params!.Name}");
@@ -373,89 +360,4 @@ public sealed class Nested
     [JsonSerializable(typeof(UnsupportedForm.Nested))]
     [JsonSerializable(typeof(JsonElement))]
     internal partial class ElicitationUnsupportedJsonContext : JsonSerializerContext;
-
-    public sealed class FormWithDefaults
-    {
-        [System.ComponentModel.DefaultValue("John Doe")]
-        public string Name { get; set; } = "John Doe";
-        
-        [System.ComponentModel.DefaultValue(30)]
-        public int Age { get; set; } = 30;
-        
-        [System.ComponentModel.DefaultValue(85.5)]
-        public double Score { get; set; } = 85.5;
-        
-        [System.ComponentModel.DefaultValue(true)]
-        public bool IsActive { get; set; } = true;
-        
-        [System.ComponentModel.DefaultValue("active")]
-        public string Status { get; set; } = "active";
-    }
-
-    [JsonSerializable(typeof(FormWithDefaults))]
-    [JsonSerializable(typeof(JsonElement))]
-    internal partial class ElicitationDefaultsJsonContext : JsonSerializerContext;
-
-    [Fact]
-    public async Task Elicit_Typed_With_Defaults_Maps_To_Schema_Defaults()
-    {
-        await using McpClient client = await CreateMcpClientForServer(new McpClientOptions
-        {
-            Handlers = new()
-            {
-                ElicitationHandler = async (request, cancellationToken) =>
-                {
-                    Assert.NotNull(request);
-                    Assert.Equal("Please provide information.", request.Message);
-
-                    Assert.Equal(5, request.RequestedSchema.Properties.Count);
-
-                    // Verify that default values from the type are mapped to the schema
-                    foreach (var entry in request.RequestedSchema.Properties)
-                    {
-                        switch (entry.Key)
-                        {
-                            case nameof(FormWithDefaults.Name):
-                                var nameSchema = Assert.IsType<ElicitRequestParams.StringSchema>(entry.Value);
-                                Assert.Equal("John Doe", nameSchema.Default);
-                                break;
-
-                            case nameof(FormWithDefaults.Age):
-                                var ageSchema = Assert.IsType<ElicitRequestParams.NumberSchema>(entry.Value);
-                                Assert.Equal(30, ageSchema.Default);
-                                break;
-
-                            case nameof(FormWithDefaults.Score):
-                                var scoreSchema = Assert.IsType<ElicitRequestParams.NumberSchema>(entry.Value);
-                                Assert.Equal(85.5, scoreSchema.Default);
-                                break;
-
-                            case nameof(FormWithDefaults.IsActive):
-                                var activeSchema = Assert.IsType<ElicitRequestParams.BooleanSchema>(entry.Value);
-                                Assert.True(activeSchema.Default);
-                                break;
-
-                            case nameof(FormWithDefaults.Status):
-                                var statusSchema = Assert.IsType<ElicitRequestParams.StringSchema>(entry.Value);
-                                Assert.Equal("active", statusSchema.Default);
-                                break;
-
-                            default:
-                                Assert.Fail($"Unexpected property: {entry.Key}");
-                                break;
-                        }
-                    }
-
-                    return new ElicitResult
-                    {
-                        Action = "accept",
-                        Content = new Dictionary<string, JsonElement>()
-                    };
-                },
-            }
-        });
-
-        var result = await client.CallToolAsync("TestElicitationWithDefaults", cancellationToken: TestContext.Current.CancellationToken);
-        Assert.Equal("success", (result.Content[0] as TextContentBlock)?.Text);
-    }
 }