.NET: [Breaking] Delete display name property (#2758)

* delete the AIAgent.DisplayName property

* use agent name as a first value for activity display name

* Update dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffAgentExecutor.cs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

dotnet/samples/GettingStarted/AgentProviders/Agent_With_CustomImplementation/Program.cs

@@ -45,7 +45,7 @@ namespace SampleApp
             }
 
             // Clone the input messages and turn them into response messages with upper case text.
-            List<ChatMessage> responseMessages = CloneAndToUpperCase(messages, this.DisplayName).ToList();
+            List<ChatMessage> responseMessages = CloneAndToUpperCase(messages, this.Name).ToList();
 
             // Notify the thread of the input and output messages.
             await typedThread.MessageStore.AddMessagesAsync(messages.Concat(responseMessages), cancellationToken);
@@ -69,7 +69,7 @@ namespace SampleApp
             }
 
             // Clone the input messages and turn them into response messages with upper case text.
-            List<ChatMessage> responseMessages = CloneAndToUpperCase(messages, this.DisplayName).ToList();
+            List<ChatMessage> responseMessages = CloneAndToUpperCase(messages, this.Name).ToList();
 
             // Notify the thread of the input and output messages.
             await typedThread.MessageStore.AddMessagesAsync(messages.Concat(responseMessages), cancellationToken);
@@ -79,7 +79,7 @@ namespace SampleApp
                 yield return new AgentRunResponseUpdate
                 {
                     AgentId = this.Id,
-                    AuthorName = this.DisplayName,
+                    AuthorName = message.AuthorName,
                     Role = ChatRole.Assistant,
                     Contents = message.Contents,
                     ResponseId = Guid.NewGuid().ToString("N"),
@@ -88,7 +88,7 @@ namespace SampleApp
             }
         }
 
-        private static IEnumerable<ChatMessage> CloneAndToUpperCase(IEnumerable<ChatMessage> messages, string agentName) => messages.Select(x =>
+        private static IEnumerable<ChatMessage> CloneAndToUpperCase(IEnumerable<ChatMessage> messages, string? agentName) => messages.Select(x =>
             {
                 // Clone the message and update its author to be the agent.
                 var messageClone = x.Clone();

dotnet/src/Microsoft.Agents.AI.A2A/A2AAgent.cs

@@ -30,7 +30,6 @@ internal sealed class A2AAgent : AIAgent
     private readonly string? _id;
     private readonly string? _name;
     private readonly string? _description;
-    private readonly string? _displayName;
     private readonly ILogger _logger;
 
     /// <summary>
@@ -40,9 +39,8 @@ internal sealed class A2AAgent : AIAgent
     /// <param name="id">The unique identifier for the agent.</param>
     /// <param name="name">The the name of the agent.</param>
     /// <param name="description">The description of the agent.</param>
-    /// <param name="displayName">The display name of the agent.</param>
     /// <param name="loggerFactory">Optional logger factory to use for logging.</param>
-    public A2AAgent(A2AClient a2aClient, string? id = null, string? name = null, string? description = null, string? displayName = null, ILoggerFactory? loggerFactory = null)
+    public A2AAgent(A2AClient a2aClient, string? id = null, string? name = null, string? description = null, ILoggerFactory? loggerFactory = null)
     {
         _ = Throw.IfNull(a2aClient);
 
@@ -50,7 +48,6 @@ internal sealed class A2AAgent : AIAgent
         this._id = id;
         this._name = name;
         this._description = description;
-        this._displayName = displayName;
         this._logger = (loggerFactory ?? NullLoggerFactory.Instance).CreateLogger<A2AAgent>();
     }
 
@@ -203,9 +200,6 @@ internal sealed class A2AAgent : AIAgent
     /// <inheritdoc/>
     public override string? Name => this._name ?? base.Name;
 
-    /// <inheritdoc/>
-    public override string DisplayName => this._displayName ?? base.DisplayName;
-
     /// <inheritdoc/>
     public override string? Description => this._description ?? base.Description;
 

dotnet/src/Microsoft.Agents.AI.A2A/Extensions/A2AClientExtensions.cs

@@ -33,9 +33,8 @@ public static class A2AClientExtensions
     /// <param name="id">The unique identifier for the agent.</param>
     /// <param name="name">The the name of the agent.</param>
     /// <param name="description">The description of the agent.</param>
-    /// <param name="displayName">The display name of the agent.</param>
     /// <param name="loggerFactory">Optional logger factory for enabling logging within the agent.</param>
     /// <returns>An <see cref="AIAgent"/> instance backed by the A2A agent.</returns>
-    public static AIAgent GetAIAgent(this A2AClient client, string? id = null, string? name = null, string? description = null, string? displayName = null, ILoggerFactory? loggerFactory = null) =>
-        new A2AAgent(client, id, name, description, displayName, loggerFactory);
+    public static AIAgent GetAIAgent(this A2AClient client, string? id = null, string? name = null, string? description = null, ILoggerFactory? loggerFactory = null) =>
+        new A2AAgent(client, id, name, description, loggerFactory);
 }

dotnet/src/Microsoft.Agents.AI.Abstractions/AIAgent.cs

@@ -60,18 +60,6 @@ public abstract class AIAgent
     /// </remarks>
     public virtual string? Name { get; }
 
-    /// <summary>
-    /// Gets a display-friendly name for the agent.
-    /// </summary>
-    /// <value>
-    /// The agent's <see cref="Name"/> if available, otherwise the <see cref="Id"/>.
-    /// </value>
-    /// <remarks>
-    /// This property provides a guaranteed non-null string suitable for display in user interfaces,
-    /// logs, or other contexts where a readable identifier is needed.
-    /// </remarks>
-    public virtual string DisplayName => this.Name ?? this.Id;
-
     /// <summary>
     /// Gets a description of the agent's purpose, capabilities, or behavior.
     /// </summary>

dotnet/src/Microsoft.Agents.AI.DevUI/EntitiesApiExtensions.cs

@@ -231,7 +231,7 @@ internal static class EntitiesApiExtensions
         return new EntityInfo(
             Id: entityId,
             Type: "agent",
-            Name: agent.DisplayName,
+            Name: agent.Name ?? agent.Id,
             Description: agent.Description,
             Framework: "agent_framework",
             Tools: tools,

dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/EndpointRouteBuilderExtensions.ChatCompletions.cs

@@ -61,7 +61,7 @@ public static partial class MicrosoftAgentAIHostingOpenAIEndpointRouteBuilderExt
 
         path ??= $"/{agent.Name}/v1/chat/completions";
         var group = endpoints.MapGroup(path);
-        var endpointAgentName = agent.DisplayName;
+        var endpointAgentName = agent.Name ?? agent.Id;
 
         group.MapPost("/", async ([FromBody] CreateChatCompletion request, CancellationToken cancellationToken)
             => await AIAgentChatCompletionsProcessor.CreateChatCompletionAsync(agent, request, cancellationToken).ConfigureAwait(false))

dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/EndpointRouteBuilderExtensions.Responses.cs

@@ -76,7 +76,7 @@ public static partial class MicrosoftAgentAIHostingOpenAIEndpointRouteBuilderExt
         var handlers = new ResponsesHttpHandler(responsesService);
 
         var group = endpoints.MapGroup(responsesPath);
-        var endpointAgentName = agent.DisplayName;
+        var endpointAgentName = agent.Name ?? agent.Id;
 
         // Create response endpoint
         group.MapPost("/", handlers.CreateResponseAsync)

dotnet/src/Microsoft.Agents.AI.Workflows/HandoffsWorkflowBuilder.cs

@@ -125,14 +125,14 @@ public sealed class HandoffsWorkflowBuilder
             {
                 Throw.ArgumentException(
                     nameof(to),
-                    $"The provided target agent '{to.DisplayName}' has no description, name, or instructions, and no handoff description has been provided. " +
+                    $"The provided target agent '{to.Name ?? to.Id}' has no description, name, or instructions, and no handoff description has been provided. " +
                     "At least one of these is required to register a handoff so that the appropriate target agent can be chosen.");
             }
         }
 
         if (!handoffs.Add(new(to, handoffReason)))
         {
-            Throw.InvalidOperationException($"A handoff from agent '{from.DisplayName}' to agent '{to.DisplayName}' has already been registered.");
+            Throw.InvalidOperationException($"A handoff from agent '{from.Name ?? from.Id}' to agent '{to.Name ?? to.Id}' has already been registered.");
         }
 
         return this;

dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/AgentRunStreamingExecutor.cs

@@ -20,7 +20,7 @@ internal sealed class AgentRunStreamingExecutor(AIAgent agent, bool includeInput
 
     protected override async ValueTask TakeTurnAsync(List<ChatMessage> messages, IWorkflowContext context, bool? emitEvents, CancellationToken cancellationToken = default)
     {
-        List<ChatMessage>? roleChanged = messages.ChangeAssistantToUserForOtherParticipants(agent.DisplayName);
+        List<ChatMessage>? roleChanged = messages.ChangeAssistantToUserForOtherParticipants(agent.Name ?? agent.Id);
 
         List<AgentRunResponseUpdate> updates = [];
         await foreach (var update in agent.RunStreamingAsync(messages, cancellationToken: cancellationToken).ConfigureAwait(false))

dotnet/src/Microsoft.Agents.AI.Workflows/Specialized/HandoffAgentExecutor.cs

@@ -67,7 +67,7 @@ internal sealed class HandoffAgentExecutor(
             List<AgentRunResponseUpdate> updates = [];
             List<ChatMessage> allMessages = handoffState.Messages;
 
-            List<ChatMessage>? roleChanges = allMessages.ChangeAssistantToUserForOtherParticipants(this._agent.DisplayName);
+            List<ChatMessage>? roleChanges = allMessages.ChangeAssistantToUserForOtherParticipants(this._agent.Name ?? this._agent.Id);
 
             await foreach (var update in this._agent.RunStreamingAsync(allMessages,
                                                                        options: this._agentOptions,
@@ -85,7 +85,7 @@ internal sealed class HandoffAgentExecutor(
                                 new AgentRunResponseUpdate
                                 {
                                     AgentId = this._agent.Id,
-                                    AuthorName = this._agent.DisplayName,
+                                    AuthorName = this._agent.Name ?? this._agent.Id,
                                     Contents = [new FunctionResultContent(fcc.CallId, "Transferred.")],
                                     CreatedAt = DateTimeOffset.UtcNow,
                                     MessageId = Guid.NewGuid().ToString("N"),

dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs

@@ -114,7 +114,9 @@ public sealed class OpenTelemetryAgent : DelegatingAIAgent, IDisposable
 
         // Override information set by OpenTelemetryChatClient to make it specific to invoke_agent.
 
-        activity.DisplayName = $"{OpenTelemetryConsts.GenAI.InvokeAgent} {this.DisplayName}";
+        activity.DisplayName = string.IsNullOrWhiteSpace(this.Name)
+            ? $"{OpenTelemetryConsts.GenAI.InvokeAgent} {this.Id}"
+            : $"{OpenTelemetryConsts.GenAI.InvokeAgent} {this.Name}({this.Id})";
         activity.SetTag(OpenTelemetryConsts.GenAI.Operation.Name, OpenTelemetryConsts.GenAI.InvokeAgent);
 
         if (!string.IsNullOrWhiteSpace(this._providerName))

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/A2AAgentTests.cs

@@ -42,16 +42,14 @@ public sealed class A2AAgentTests : IDisposable
         const string TestId = "test-id";
         const string TestName = "test-name";
         const string TestDescription = "test-description";
-        const string TestDisplayName = "test-display-name";
 
         // Act
-        var agent = new A2AAgent(this._a2aClient, TestId, TestName, TestDescription, TestDisplayName);
+        var agent = new A2AAgent(this._a2aClient, TestId, TestName, TestDescription);
 
         // Assert
         Assert.Equal(TestId, agent.Id);
         Assert.Equal(TestName, agent.Name);
         Assert.Equal(TestDescription, agent.Description);
-        Assert.Equal(TestDisplayName, agent.DisplayName);
     }
 
     [Fact]
@@ -70,7 +68,6 @@ public sealed class A2AAgentTests : IDisposable
         Assert.NotEmpty(agent.Id);
         Assert.Null(agent.Name);
         Assert.Null(agent.Description);
-        Assert.Equal(agent.Id, agent.DisplayName);
     }
 
     [Fact]

dotnet/tests/Microsoft.Agents.AI.A2A.UnitTests/Extensions/A2AClientExtensionsTests.cs

@@ -19,10 +19,9 @@ public sealed class A2AClientExtensionsTests
         const string TestId = "test-agent-id";
         const string TestName = "Test Agent";
         const string TestDescription = "This is a test agent description";
-        const string TestDisplayName = "Test Display Name";
 
         // Act
-        var agent = a2aClient.GetAIAgent(TestId, TestName, TestDescription, TestDisplayName);
+        var agent = a2aClient.GetAIAgent(TestId, TestName, TestDescription);
 
         // Assert
         Assert.NotNull(agent);
@@ -30,6 +29,5 @@ public sealed class A2AClientExtensionsTests
         Assert.Equal(TestId, agent.Id);
         Assert.Equal(TestName, agent.Name);
         Assert.Equal(TestDescription, agent.Description);
-        Assert.Equal(TestDisplayName, agent.DisplayName);
     }
 }

dotnet/tests/Microsoft.Agents.AI.UnitTests/LoggingAgentTests.cs

@@ -42,7 +42,6 @@ public class LoggingAgentTests
         Assert.Equal("TestAgent", agent.Name);
         Assert.Equal("This is a test agent.", agent.Description);
         Assert.Equal(innerAgent.Id, agent.Id);
-        Assert.Equal(innerAgent.DisplayName, agent.DisplayName);
     }
 
     [Fact]

dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs

@@ -45,7 +45,6 @@ public class OpenTelemetryAgentTests
         Assert.Equal("TestAgent", agent.Name);
         Assert.Equal("This is a test agent.", agent.Description);
         Assert.Equal(innerAgent.Id, agent.Id);
-        Assert.Equal(innerAgent.DisplayName, agent.DisplayName);
     }
 
     [Fact]
@@ -170,7 +169,7 @@ public class OpenTelemetryAgentTests
         Assert.Equal("localhost", activity.GetTagItem("server.address"));
         Assert.Equal(12345, (int)activity.GetTagItem("server.port")!);
 
-        Assert.Equal("invoke_agent TestAgent", activity.DisplayName);
+        Assert.Equal($"invoke_agent {agent.Name}({agent.Id})", activity.DisplayName);
         Assert.Equal("invoke_agent", activity.GetTagItem("gen_ai.operation.name"));
         Assert.Equal("TestAgentProviderFromAIAgentMetadata", activity.GetTagItem("gen_ai.provider.name"));
         Assert.Equal(innerAgent.Name, activity.GetTagItem("gen_ai.agent.name"));
@@ -431,7 +430,15 @@ public class OpenTelemetryAgentTests
         Assert.Equal("localhost", activity.GetTagItem("server.address"));
         Assert.Equal(12345, (int)activity.GetTagItem("server.port")!);
 
-        Assert.Equal($"invoke_agent {innerAgent.DisplayName}", activity.DisplayName);
+        if (string.IsNullOrWhiteSpace(innerAgent.Name))
+        {
+            Assert.Equal($"invoke_agent {innerAgent.Id}", activity.DisplayName);
+        }
+        else
+        {
+            Assert.Equal($"invoke_agent {innerAgent.Name}({innerAgent.Id})", activity.DisplayName);
+        }
+
         Assert.Equal("invoke_agent", activity.GetTagItem("gen_ai.operation.name"));
         Assert.Equal("TestAgentProviderFromAIAgentMetadata", activity.GetTagItem("gen_ai.provider.name"));
         Assert.Equal(innerAgent.Name, activity.GetTagItem("gen_ai.agent.name"));

dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/Sample/12_HandOff_HostAsAgent.cs

@@ -30,7 +30,7 @@ internal sealed class HandoffTestEchoAgent(string id, string name, string prefix
                 {
                     return [new(ChatRole.Assistant, [new FunctionCallContent(Guid.NewGuid().ToString("N"), handoff.Name)])
                     {
-                        AuthorName = this.DisplayName,
+                        AuthorName = this.Name ?? this.Id,
                         MessageId = Guid.NewGuid().ToString("N"),
                         CreatedAt = DateTime.UtcNow
                     }];

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

@@ -47,7 +47,7 @@ internal class TestEchoAgent(string? id = null, string? name = null, string? pre
               select
                     UpdateThread(new ChatMessage(ChatRole.Assistant, $"{prefix}{message.Text}")
                     {
-                        AuthorName = this.DisplayName,
+                        AuthorName = this.Name ?? this.Id,
                         CreatedAt = DateTimeOffset.Now,
                         MessageId = Guid.NewGuid().ToString("N")
                     }, thread as InMemoryAgentThread);