fix: declare Magentic protocol messages (microsoft#5778)

Co-authored-by: Jacob Alber <jaalber@microsoft.com>

Author: he-yufeng

dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/Magentic/MagenticOrchestrator.cs

@@ -98,7 +98,10 @@ internal class MagenticOrchestrator(AIAgent managerAgent, List<AIAgent> team, Ta
 
     protected override ProtocolBuilder ConfigureProtocol(ProtocolBuilder protocolBuilder)
     {
-        return base.ConfigureProtocol(protocolBuilder).ConfigureRoutes(ConfigureRoutes);
+        return base.ConfigureProtocol(protocolBuilder)
+                   .SendsMessage<ChatMessage>()
+                   .SendsMessage<ResetChatSignal>()
+                   .ConfigureRoutes(ConfigureRoutes);
 
         void ConfigureRoutes(RouteBuilder routeBuilder) => routeBuilder.AddPortHandler<MagenticPlanReviewRequest, MagenticPlanReviewResponse>(
                 "RequestPlanReview",

dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/MagenticOrchestratorTests.cs

@@ -0,0 +1,26 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Collections.Generic;
+using FluentAssertions;
+using Microsoft.Agents.AI.Workflows.Specialized.Magentic;
+using Microsoft.Extensions.AI;
+
+namespace Microsoft.Agents.AI.Workflows.UnitTests;
+
+public class MagenticOrchestratorTests
+{
+    [Fact]
+    public void Test_MagenticOrchestrator_Protocol_Declares_SentMessages()
+    {
+        TestReplayAgent manager = new(name: nameof(MagenticOrchestrator));
+        TestEchoAgent participant = new(name: "Echo");
+        MagenticOrchestrator orchestrator = new(manager, [participant], new(), requirePlanSignoff: false);
+
+        ProtocolDescriptor protocol = orchestrator.DescribeProtocol();
+
+        protocol.Sends.Should().Contain(typeof(List<ChatMessage>));
+        protocol.Sends.Should().Contain(typeof(ChatMessage));
+        protocol.Sends.Should().Contain(typeof(TurnToken));
+        protocol.Sends.Should().Contain(typeof(ResetChatSignal));
+    }
+}