.NET: Investigation: .NET OTel auto-instrumentation convention for Agent Framework

[rogerbarreto]

Objective

Big OTel rock in .NET land. Tribe pattern say: AddXxxInstrumentation() on provider, kill switch env var, separate package. Tribe use ASP.NET Core, Azure SDK, EF Core. Same shape.

Agent Framework today: must wrap each agent by hand with UseOpenTelemetry(). No tribe pattern. No kill switch. No one-line activate.

Need investigate. Not code yet. Lay stone first:

• Where instrumentation live? Core? New Microsoft.Agents.AI.OpenTelemetry package? Contrib OpenTelemetry.Instrumentation.AgentFramework (open-telemetry tribe own OpenTelemetry.* prefix on nuget, can't take)?
• How activate? DI auto-decorate AIAgent? Provider builder extension? Both? Idempotent?
• Kill switch env var name? OTEL_DOTNET_AGENTFRAMEWORK_INSTRUMENTATION_ENABLED?
• Source name rename? Today Experimental.Microsoft.Agents.AI. Tribe say Microsoft.Agents.AI.
• Workflows source Microsoft.Agents.AI.Workflows same package?
• Long term: move emit into base AIAgent BCL ActivitySource listener-driven (like HttpClient)? Skip wrapper?
• Future: contrib package shim post-GA, post-stable gen-AI semconv?

Land ADR with options + decision before any code. Existing ADR 0003 stay. New ADR add on top.

Outcome

ADR docs/decisions/0026-agent-otel-auto-instrumentation.md proposed, reviewed, accepted. Then implementation issue spin off.

Refs

• ADR 0003 (current OpenTelemetryAgent wrapper)
• https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/versioning-and-stability.md
• https://github.com/open-telemetry/opentelemetry-dotnet-instrumentation/blob/main/docs/config.md
• https://www.nuget.org/packages/OpenTelemetry.Instrumentation.AspNetCore