fix(orchestration): name the provider's words when a worker's preamble is rejected (#35791)

When a structured worker's dispatch preamble is definitively rejected, the
dispatch_preamble_undelivered error now appends the provider's failure detail
("Details: ...") unless the rejection sentence already quotes it. The quoted
text is bounded and normalized by the same quotedProviderDetail helper the
rejection writer uses.

Co-authored-by: Neil <4138956+nwparker@users.noreply.github.com>

src/main/runtime/rpc/methods/orchestration-structured-worker-session.test.ts

@@ -7,6 +7,8 @@ import type { AgentJournalSubmission } from '../../../../shared/agent-session-jo
 import type { AgentMessageSource } from '../../../../shared/agent-session/agent-session-message-source'
 import { getAppEnvironment } from '../../../../shared/app-environment'
 import { DISPATCH_REJECTED_WRITE_FAILED } from '../../../../shared/structured-agent-session-dispatch-rejection'
+import { agentSessionFailureFact } from '../../../../shared/agent-session-failure'
+import { codexDispatchRejection } from '../../../codex/codex-structured-turn-end-settlement'
 
 const hostRef: { current: unknown } = { current: null }
 const createSpy = vi.fn()
@@ -231,7 +233,7 @@ describe('structured worker session', () => {
 
 describe('structured worker dispatch preamble', () => {
   type PreambleHost = Parameters<typeof sendStructuredWorkerPreamble>[0]['host']
-  type Settled = Pick<AgentJournalSubmission, 'dispatchState' | 'reason'>
+  type Settled = Pick<AgentJournalSubmission, 'dispatchState' | 'reason' | 'rejection'>
 
   function submissionOf(settled: Settled): AgentJournalSubmission {
     return {
@@ -377,6 +379,43 @@ describe('structured worker dispatch preamble', () => {
     expect(isUnknownWorkerStartOutcome(error, 'dispatch_input')).toBe(false)
   })
 
+  it('names a provider log detail the rejection sentence leaves out', async () => {
+    const error = await send(
+      hostWithSubmission({
+        dispatchState: 'rejected',
+        ...codexDispatchRejection(
+          agentSessionFailureFact('providerRejected', {
+            detail: { text: 'thread/start: unsupported service tier', audience: 'log' },
+            neverReachedAgent: true
+          })
+        )
+      })
+    ).catch((thrown: unknown) => thrown)
+    expect(error).toMatchObject({
+      code: 'dispatch_preamble_undelivered',
+      message:
+        "The dispatch preamble was not delivered (providerRejected): Codex didn't accept this message. Details: thread/start: unsupported service tier."
+    })
+  })
+
+  it('does not repeat provider words the rejection sentence already quotes', async () => {
+    const error = await send(
+      hostWithSubmission({
+        dispatchState: 'rejected',
+        ...codexDispatchRejection(
+          agentSessionFailureFact('providerRejected', {
+            detail: { text: 'Unsupported service tier.', audience: 'person' },
+            neverReachedAgent: true
+          })
+        )
+      })
+    ).catch((thrown: unknown) => thrown)
+    expect(error).toMatchObject({
+      message:
+        "The dispatch preamble was not delivered (providerRejected): Codex didn't accept this message: Unsupported service tier."
+    })
+  })
+
   it('ends the message with one period whether the reason is a sentence or a marker', async () => {
     const sentence = await send(
       hostWithSubmission({

src/main/runtime/rpc/methods/orchestration-structured-worker-session.ts

@@ -4,6 +4,11 @@
 import { randomUUID } from 'node:crypto'
 import { isDefinitiveAgentSessionCreateRefusal } from '../../../../shared/agent-session-definitive-refusal'
 import type { AgentMessageSource } from '../../../../shared/agent-session/agent-session-message-source'
+import {
+  agentSessionFailureDetailText,
+  readAgentSessionFailureFact
+} from '../../../../shared/agent-session-failure'
+import { quotedProviderDetail } from '../../../../shared/agent-session-failure-quoted-detail'
 import type {
   AgentJournalMessageItem,
   AgentJournalSubmission
@@ -240,12 +245,17 @@ export function preambleDispatchState(
     return submission.dispatchState
   }
   if (submission?.dispatchState === 'rejected') {
+    // Name the failure detail unless the reason already quotes it.
+    const detail = agentSessionFailureDetailText(readAgentSessionFailureFact(submission.rejection))
+    const quoted = detail ? quotedProviderDetail(detail) : ''
+    const detailClause =
+      quoted && !submission.reason?.includes(quoted) ? ` Details: ${quoted}.` : ''
     // Definitive rejection gets a typed non-delivery code so the coordinator can retry without a duplicate turn.
     throw new OrchestrationError(
       'dispatch_preamble_undelivered',
       `The dispatch preamble was not delivered${
         submission.rejection ? ` (${submission.rejection.kind})` : ''
-      }: ${reasonClause(submission.reason)}.`
+      }: ${reasonClause(submission.reason)}.${detailClause}`
     )
   }
   // Only accepted proves delivery; adapter/transport unknown requires an outcome_unknown receipt that tells the coordinator to inspect.

src/shared/agent-session-failure-quoted-detail.ts

@@ -8,6 +8,14 @@ import type {
 /** Person-facing provider text is quoted, but bounded so the sentence stays one. */
 const MAX_QUOTED_DETAIL_CHARS = 512
 
+/** Provider text as a failure sentence quotes it. */
+export function quotedProviderDetail(text: string): string {
+  return text
+    .slice(0, MAX_QUOTED_DETAIL_CHARS)
+    .trim()
+    .replace(/[.\s]+$/, '')
+}
+
 /** The quoted lead when the provider wrote the detail for a person; the plain lead otherwise. */
 export function quotingPersonDetail(
   say: AgentSessionFailureSay,
@@ -16,12 +24,6 @@ export function quotingPersonDetail(
   detail: ProviderDiagnostic | undefined,
   values: AgentSessionFailureCopyValues = {}
 ): string {
-  const quoted =
-    detail?.audience === 'person'
-      ? detail.text
-          .slice(0, MAX_QUOTED_DETAIL_CHARS)
-          .trim()
-          .replace(/[.\s]+$/, '')
-      : ''
+  const quoted = detail?.audience === 'person' ? quotedProviderDetail(detail.text) : ''
   return quoted ? say(quotedLead, { ...values, detail: quoted }) : say(lead, values)
 }