Declarative CustomerSupport: how should a host uniformly render UserMessage from output?

[likebean]

Question

In the declarative Customer Support sample, escalate_agent uses structured output (IsComplete + UserMessage) together with externalLoop and autoSend: true. We want the end user to see UserMessage (natural language), not the raw JSON.

Our host must render user-facing text uniformly from the action output. It cannot special-case individual agents or field names (UserMessage vs Reply vs ClarificationQuestion, etc.).

What is the intended way to do that in this sample?

Sample

declarative-agents/workflow-samples/CustomerSupport.yaml (escalate_agent):

- kind: InvokeAzureAgent
  id: escalate_agent
  conversationId: =Local.EscalationConversationId
  agent:
    name: TicketEscalationAgent
  input:
    arguments:
      TicketId: =Local.TicketParameters.TicketId
      IssueDescription: =Local.ServiceParameters.IssueDescription
      ResolutionSummary: =Local.ResolutionSteps
    externalLoop:
      when: =Not(Local.EscalationParameters.IsComplete)
  output:
    autoSend: true
    responseObject: Local.EscalationParameters

The agent is constrained to a JSON schema like:

class EscalationResponse(BaseModel):
    IsComplete: bool
    UserMessage: str

(See the matching Python / .NET Customer Support samples.)

What we observe

• responseObject: Local.EscalationParameters correctly parses the JSON for workflow state / when.
• autoSend: true yields the agent's raw text, which is the whole JSON object when response_format is set.
• output appears to only support autoSend (bool), responseObject, and messages. There is no output property that identifies which field is the user-visible message.

We would like to hear from maintainers how a host is supposed to surface UserMessage in this pattern, given the constraint above. Thanks.