フリー問題

問題文

A team wants distributed tracing across their MCP calls. Which mechanism does the specification document for this?

選択肢

1. There is no documented mechanism; teams must define their own vendor-prefixed keys.
2. The reserved _meta keys traceparent, tracestate, and baggage, whose values follow the W3C trace context and baggage formats.
3. The logging feature, which is the specification's recommended observability mechanism for carrying trace identifiers between hops.
4. A dedicated tracing capability that both sides negotiate, after which the server emits span notifications on the subscriptions/listen stream so that the client can assemble the trace without having to correlate anything itself.