.NET: fix: allow naming handoff workflows (#5799)

* fix: allow naming handoff workflows

* Only set name/description if not NullOrWhitespace

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

---------

Co-authored-by: Jacob Alber <jalber@fernir.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Jacob Alber <jaalber@microsoft.com>

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

@@ -54,6 +54,8 @@ public class HandoffWorkflowBuilderCore<TBuilder> where TBuilder : HandoffWorkfl
     private bool _emitAgentResponseUpdateEvents;
     private HandoffToolCallFilteringBehavior _toolCallFilteringBehavior = HandoffToolCallFilteringBehavior.HandoffOnly;
     private bool _returnToPrevious;
+    private string? _name;
+    private string? _description;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="HandoffsWorkflowBuilder"/> class with no handoff relationships.
@@ -97,6 +99,20 @@ public class HandoffWorkflowBuilderCore<TBuilder> where TBuilder : HandoffWorkfl
         return (TBuilder)this;
     }
 
+    /// <inheritdoc cref="WorkflowBuilder.WithName(string)"/>
+    public TBuilder WithName(string name)
+    {
+        this._name = name;
+        return (TBuilder)this;
+    }
+
+    /// <inheritdoc cref="WorkflowBuilder.WithDescription(string)"/>
+    public TBuilder WithDescription(string description)
+    {
+        this._description = description;
+        return (TBuilder)this;
+    }
+
     /// <summary>
     /// Sets a value indicating whether agent streaming update events should be emitted during execution.
     /// If <see langword="null"/>, the value will be taken from the <see cref="TurnToken"/>
@@ -330,7 +346,16 @@ public class HandoffWorkflowBuilderCore<TBuilder> where TBuilder : HandoffWorkfl
             builder.AddEdge(start, executors[this._initialAgent.Id]);
         }
 
-        // Build the workflow.
+        if (!string.IsNullOrWhiteSpace(this._name))
+        {
+            builder.WithName(this._name);
+        }
+
+        if (!string.IsNullOrWhiteSpace(this._description))
+        {
+            builder.WithDescription(this._description);
+        }
+
         return builder.WithOutputFrom(end).Build();
     }
 }

dotnet/tests/Microsoft.Agents.AI.Hosting.UnitTests/HostApplicationBuilderWorkflowExtensionsTests.cs

@@ -103,6 +103,30 @@ public class HostApplicationBuilderWorkflowExtensionsTests
         Assert.Contains(workflowDescriptors, d => (string)d.ServiceKey! == "workflow3");
     }
 
+    /// <summary>
+    /// Verifies that a handoff workflow can be named from the DI workflow key.
+    /// </summary>
+    [Fact]
+    public void AddWorkflow_HandoffWorkflowWithName_ResolvesWorkflow()
+    {
+        var builder = new HostApplicationBuilder();
+        const string WorkflowName = "handoffWorkflow";
+
+        var mockAgent = new Mock<AIAgent>();
+        mockAgent.Setup(a => a.Name).Returns("handoffAgent");
+
+#pragma warning disable MAAIW001 // This test covers hosting handoff workflows.
+        builder.AddWorkflow(WorkflowName, (sp, key) =>
+            AgentWorkflowBuilder.CreateHandoffBuilderWith(mockAgent.Object)
+                .WithName(key)
+                .Build());
+#pragma warning restore MAAIW001
+
+        var workflow = builder.Build().Services.GetRequiredKeyedService<Workflow>(WorkflowName);
+
+        Assert.Equal(WorkflowName, workflow.Name);
+    }
+
     /// <summary>
     /// Verifies that AddWorkflow handles empty strings for name.
     /// </summary>

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

@@ -86,6 +86,23 @@ public class HandoffOrchestrationTests
         target.Reason.Should().Be("instructions");
     }
 
+    [Fact]
+    public void BuildHandoffs_WithNameAndDescription_SetsWorkflowMetadata()
+    {
+        const string WorkflowName = "handoff-workflow";
+        const string WorkflowDescription = "A handoff workflow";
+
+        DoubleEchoAgent agent = new("agent");
+
+        var workflow = AgentWorkflowBuilder.CreateHandoffBuilderWith(agent)
+            .WithName(WorkflowName)
+            .WithDescription(WorkflowDescription)
+            .Build();
+
+        Assert.Equal(WorkflowName, workflow.Name);
+        Assert.Equal(WorkflowDescription, workflow.Description);
+    }
+
     [Fact]
     public async Task Handoffs_NoTransfers_ResponseServedByOriginalAgentAsync()
     {