feat: Add name and description support to workflows (#1183)

Add optional name and description fields to workflows in both Python and .NET implementations, matching the existing agent API pattern.

Python changes:
- Add name/description parameters to WorkflowBuilder.__init__
- Add name/description attributes to Workflow class
- Include name/description in to_dict() serialization
- Add WORKFLOW_NAME and WORKFLOW_DESCRIPTION OTEL attributes
- Add tests in test_serialization.py and test_workflow_observability.py

.NET changes:
- Add Name and Description properties to Workflow and Workflow<T>
- Add WithName() and WithDescription() fluent methods to WorkflowBuilder
- Add WorkflowName and WorkflowDescription OTEL tags
- Add test in WorkflowBuilderSmokeTests.cs

This enables applications like DevUI to display human-readable workflow names (e.g., 'Data Processing Pipeline') instead of auto-generated UUIDs (e.g., 'Workflow 50fdd917').

Fixes: #1181

python/packages/core/tests/workflow/test_serialization.py

@@ -599,6 +599,48 @@ class TestSerializationWorkflowClasses:
         assert "_shared_state" not in data
         assert "_runner" not in data
 
+    def test_workflow_name_description_serialization(self) -> None:
+        """Test that workflow name and description are serialized correctly."""
+        # Test 1: With name and description
+        workflow1 = (
+            WorkflowBuilder(name="Test Pipeline", description="Test workflow description")
+            .set_start_executor(SampleExecutor(id="e1"))
+            .build()
+        )
+
+        assert workflow1.name == "Test Pipeline"
+        assert workflow1.description == "Test workflow description"
+
+        data1 = workflow1.to_dict()
+        assert data1["name"] == "Test Pipeline"
+        assert data1["description"] == "Test workflow description"
+
+        # Test JSON serialization
+        json_str1 = workflow1.to_json()
+        parsed1 = json.loads(json_str1)
+        assert parsed1["name"] == "Test Pipeline"
+        assert parsed1["description"] == "Test workflow description"
+
+        # Test 2: Without name and description (defaults)
+        workflow2 = WorkflowBuilder().set_start_executor(SampleExecutor(id="e2")).build()
+
+        assert workflow2.name is None
+        assert workflow2.description is None
+
+        data2 = workflow2.to_dict()
+        assert "name" not in data2  # Should not include None values
+        assert "description" not in data2
+
+        # Test 3: With only name (no description)
+        workflow3 = WorkflowBuilder(name="Named Only").set_start_executor(SampleExecutor(id="e3")).build()
+
+        assert workflow3.name == "Named Only"
+        assert workflow3.description is None
+
+        data3 = workflow3.to_dict()
+        assert data3["name"] == "Named Only"
+        assert "description" not in data3
+
     def test_executor_field_validation(self) -> None:
         """Test that Executor field validation works correctly."""
         # Valid executor

python/packages/core/tests/workflow/test_workflow_observability.py

@@ -282,6 +282,23 @@ async def test_end_to_end_workflow_tracing(span_exporter: InMemorySpanExporter)
     assert "build.validation_completed" in build_event_names
     assert "build.completed" in build_event_names
 
+    # Clear spans to test workflow with name and description
+    span_exporter.clear()
+
+    # Test workflow with name and description - verify OTEL attributes
+    (
+        WorkflowBuilder(name="Test Pipeline", description="Test workflow description")
+        .set_start_executor(MockExecutor("start"))
+        .build()
+    )
+
+    build_spans_with_metadata = [s for s in span_exporter.get_finished_spans() if s.name == "workflow.build"]
+    assert len(build_spans_with_metadata) == 1
+    metadata_build_span = build_spans_with_metadata[0]
+    assert metadata_build_span.attributes is not None
+    assert metadata_build_span.attributes.get(OtelAttr.WORKFLOW_NAME) == "Test Pipeline"
+    assert metadata_build_span.attributes.get(OtelAttr.WORKFLOW_DESCRIPTION) == "Test workflow description"
+
     # Clear spans to separate build from run tracing
     span_exporter.clear()