[Vincent Biret (baywet)]

Motivation & Context

Align .NET workflow invocation telemetry with the pinned OpenTelemetry GenAI invoke-workflow conventions. The existing instrumentation emits workflow_invoke, uses the nonstandard workflow.name key only on build activities, omits the required operation attribute, and does not record application-supplied conversation context on invocation activities. These inconsistencies make standard queries, sampling, and conversation correlation harder.

Description & Review Guide

• What are the major changes? Emit invoke_workflow {gen_ai.workflow.name} for named workflows and bare invoke_workflow when no meaningful name exists. Replace workflow.name with gen_ai.workflow.name on build activities and propagate the name through both execution paths onto invocation activities. Record gen_ai.operation.name="invoke_workflow" at activity creation, keeping its value independent of the workflow-name suffix. Also record a supplied gen_ai.conversation.id from OpenTelemetry baggage, falling back to the current Activity's baggage; non-blank OpenTelemetry baggage takes precedence. Add regression coverage and update telemetry option documentation and the .NET consumer observability reference.
• What is the impact of these changes? This is a breaking telemetry change, not a public API signature or workflow execution change. Update dashboards, exporters, and filters from workflow_invoke to the new span-name format and from workflow.name to gen_ai.workflow.name. To identify invocation activities independently of their workflow names, filter on gen_ai.operation.name="invoke_workflow". For conversation correlation, supply gen_ai.conversation.id through OpenTelemetry or Activity baggage before running the workflow. Missing/blank conversation IDs are omitted; execution session.id is preserved and is never repurposed as a fallback conversation ID. This does not automatically infer conversation IDs from workflow-as-agent sessions or declarative backend state. Framework-specific build/session/executor/message span names and unrelated custom attributes remain unchanged.
• What do you want reviewers to focus on? Name propagation for named and unnamed workflows across Lockstep, OffThread, and Concurrent execution, with streaming and non-streaming APIs; creation-time availability of the semantic attributes and full span name; keeping the base operation value unchanged; conversation-context precedence and omission without context; and preservation of named-span stopping, exportability, and parent relationships. Existing prefix-based activity lookups remain compatible. Python already supports scoped conversation IDs, including supplied AG-UI thread IDs, and Python: [BREAKING] align workflow span name with OpenTelemetry conventions #9900 preserves that behavior for named spans; no Python changes are included here.

From dotnet, the following commands passed:

dotnet build src\Microsoft.Agents.AI.Workflows\Microsoft.Agents.AI.Workflows.csproj --no-restore --tl:off
# Passed for net472, netstandard2.0, net8.0, net9.0, and net10.0; 0 warnings, 0 errors.

dotnet run --project tests\Microsoft.Agents.AI.Workflows.UnitTests -f net10.0 --no-restore -- --progress off
# Passed: all 928 workflow unit tests.

dotnet run --project tests\Microsoft.Agents.AI.Workflows.UnitTests -f net10.0 --no-restore -- --filter-class '*ObservabilityTests' --progress off
# Passed: all 55 observability cases, including conversation propagation and omission regressions.

dotnet run --project tests\Microsoft.Agents.AI.Workflows.Declarative.UnitTests -f net10.0 --no-restore -- --filter-class '*DeclarativeWorkflowOptionsTest' --progress off
# Passed: 10 declarative telemetry/configuration tests.

Changed production and workflow-test files were formatted in their respective projects after each implementation step. The final conversation-ID formatting commands were:

dotnet format src\Microsoft.Agents.AI.Workflows\Microsoft.Agents.AI.Workflows.csproj --no-restore --include src\Microsoft.Agents.AI.Workflows\Observability\Tags.cs src\Microsoft.Agents.AI.Workflows\Observability\WorkflowTelemetryContext.cs
# Passed.

dotnet format tests\Microsoft.Agents.AI.Workflows.UnitTests\Microsoft.Agents.AI.Workflows.UnitTests.csproj --no-restore --include tests\Microsoft.Agents.AI.Workflows.UnitTests\ObservabilityTests.cs
# Passed.

The initial declarative-test expectation change was also formatted:

dotnet format tests\Microsoft.Agents.AI.Workflows.Declarative.UnitTests --no-restore --verbosity minimal
# Passed.

The full solution test suite and integration tests were not run. Python source and existing regression tests were inspected, not rerun.

Related Issue

N/A - trivial change: correct unambiguous workflow invocation span/attribute mismatches with the linked specification. No competing open .NET workflow telemetry-alignment PR was found. #9900 is the complementary Python change, not a duplicate.

AI Assistance

• No material AI assistance was used.
• This is an AI-assisted contribution. I reviewed, understood, and verified all submitted content and accept responsibility for it.

AI assistance details: GitHub Copilot assisted with implementation, regression tests, documentation, validation, the Python behavior comparison, and this PR description.

Contribution Checklist

• The code builds clean without any errors or warnings
• All unit tests pass, and I have added new tests where possible
• The PR follows the Contribution Guidelines
• This PR links to an agreed issue with no competing open PR, or the Related Issue section documents a trivial-change or repository-automation exception.
• This is not a breaking change. If it is a breaking change, add the breaking change label (or add "[BREAKING]" to the title prefix, before or after any language prefix) — a workflow keeps the label and title prefix in sync automatically.

[Copilot]

🟢 Approval recommended

The workflow invocation span-name correction has no active review issues.

No open issues 🎉

What changed in this PR

Corrects the .NET workflow invocation span name from workflow_invoke to invoke_workflow to align with OpenTelemetry conventions. Telemetry filters using the old name will need updating.

Changes:

• Updates the shared span-name constant and declarative telemetry expectation.
• Adds six regression cases covering streaming and non-streaming execution across Lockstep, OffThread, and Concurrent environments.
• Aligns API documentation and existing test comments with the corrected name.

File	Description
dotnet/​tests/​Microsoft.Agents.AI.Workflows.UnitTests/​WorkflowRunActivityStopTests.cs	Updates comments only to use the corrected span name.
dotnet/​tests/​Microsoft.Agents.AI.Workflows.UnitTests/​ObservabilityTests.cs	Adds six cases asserting the literal convention name.
dotnet/​tests/​Microsoft.Agents.AI.Workflows.Declarative.UnitTests/​DeclarativeWorkflowOptionsTest.cs	Updates the expected invocation span name.
dotnet/​src/​Microsoft.Agents.AI.Workflows/​Observability/​WorkflowTelemetryOptions.cs	Corrects the span name in API documentation.
dotnet/​src/​Microsoft.Agents.AI.Workflows/​Observability/​ActivityNames.cs	Changes the shared invocation span-name constant.

_{Review effort: Balanced}

[github-actions]

MAF Automated Review — Iteration 1

Result: No findings
Scope: full PR (1 commit(s)): c0fa63f0d9bb
Model: gpt-5.6-sol

Overview

The PR centralizes the corrected invoke_workflow activity name in the existing internal constant and updates its public documentation and declarative expectation consistently. The new regression covers streaming and non-streaming runs across Lockstep, OffThread, and Concurrent execution, while existing tests preserve activity enablement, routing, and disposal guarantees. No PR-introduced Critical, High, or Medium defect remains after reconciliation.

Reviewed the supplied pull-request change set across correctness, security/reliability, architecture, and failure behavior.
No publishable findings remained after source verification for this scope.

[github-code-quality]

Code coverage overview

Languages: C#

C# / code-coverage/dotnet

main f148334	fix/workflow-span-na... 95d38a6	+/-
86%	86%	0%

View coverage of the 4 most impacted files.

File	main f148334	fix/workflow-span-na... 95d38a6	+/-
/home/runner/wo...SessionStore.cs	100%	56%	-44%
/home/runner/wo...kflowBuilder.cs	90%	90%	0%
/home/runner/wo...metryContext.cs	90%	91%	+1%
/home/runner/wo...rocessRunner.cs	91%	92%	+1%

ℹ️ Calculations represent line coverage. Results may change as calculations are updated.

---

_{Updated November 02, 2026 18:19 UTC}

[Copilot]

🟡 Changes recommended

Selective sampling can clear Activity.Current when no workflow session activity is created, causing invocations to lose the application's gen_ai.conversation.id baggage; the ambient activity must be preserved and covered by a regression test.

1 open issue

• Preserve ambient activity when workflow session sampling is skipped · New

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

No active review issues are reported for the .NET workflow telemetry alignment with OpenTelemetry GenAI conventions.

No open issues 🎉

1 resolved since last review

• Preserve ambient activity when workflow session sampling is skipped

_{Review effort: Balanced}