# Control Event Intent Proportionality

<!-- auto-oncall-optimization-record
{
  "schemaVersion": "auto-oncall-optimization-record-v1",
  "optimizationId": "control-event-intent-proportionality-2026-07-23",
  "problems": [
    {
      "problemId": "control-event-answer-overexplains-unasked-controls",
      "summary": "The support reply contract requires switch, frequency, parent-feature side-effect, and handling details even when a customer only asks what a control event is or why it appears.",
      "status": "optimized_verified",
      "issueKeys": ["ST-2835"],
      "sourceRefs": ["https://tidb.atlassian.net/browse/ST-2835#problem:control-event-answer-overexplains-unasked-controls"],
      "signalTextIncludesAny": ["没有询问控制方式", "不需要每个 case 全量输出", "用户不理解的场景下进行引导"],
      "observedThrough": "2026-07-23",
      "effectiveAt": "2026-07-23T07:14:28Z",
      "verifiedAt": "2026-07-23T07:20:26Z",
      "attemptedAction": "Change control-event reply guidance to explain meaning and cause by default, add only concise guidance for customer misunderstanding, and expand control boundaries only for explicit disable, frequency, suppression, handling, or parent-feature intent.",
      "evidenceUrl": "https://tidb.atlassian.net/rest/servicedeskapi/request/7911726/comment/23259827"
    }
  ]
}
-->

- Optimization ID: `control-event-intent-proportionality-2026-07-23`
- Owner: Codex implementation requested on 2026-07-23
- Source reference: follow-up review of the ST-2835 answer-completeness optimization
- Implementation status: merged and deployed to staging
- Effective status: `optimized_verified`

## Bounded problem

The earlier ST-2835 optimization preserved useful TiCDC WATERMARK product
boundaries, but made the full control inventory an answer requirement even
when a customer only asks what an event is or why it appears. That can make a
simple explanatory answer longer than the customer's intent requires.

## Intended change

Keep the established control-event knowledge while making response depth
proportional to intent:

- Explain event meaning and cause by default.
- Add one concise handling cue when the customer mistakes a control event for
  business data or unexplained noise.
- Expand switch, frequency, parent-feature side-effect, and least-disruptive
  handling details only for explicit control or handling intent.

## Verification

- Focused support-reply-format and optimization-record tests passed 5/5; the
  complete repository suite passed 407/407 across 50 suites.
- The change merged in `tidbcloud/aisupport#468`. Staging workflow
  `29987192759` built image
  `cf8d872c404d188ef7aaa73cc0ec67f9994cb414`, and app-delivery PR
  `tidbcloud/app-delivery#75248` rolled it out.
- The live Deployment reached 1/1 Ready on the new image; `/readyz` and
  `/healthz` returned HTTP 200. Poller and worker logs were healthy and idle,
  and the DB had no queued, running, or retryable-failed jobs.
- Read replay `41718823-eea1-4034-97b3-b0f0c21ae6f1` answered only why
  WATERMARK can appear without DML, clarified that it is not business data,
  and added one consumer-side handling cue. It did not volunteer switch,
  frequency, or parent-feature side-effect details.
- Write replay `8f62611c-fca8-4bea-8748-9ce744c43d47` (DB run `60101`)
  updated existing Jira internal comment `23259827` through
  `auto-live:v1:ST-2835:initial`. JSM API readback returned HTTP 200 and
  `public=false`; no duplicate comment was created.

## Unresolved gaps

- The bounded over-explanation problem is verified for ST-2835.
- The explicit suppression path remains protected by its contract test. A
  future natural case can add live evidence, but it is not required to verify
  the separate problem of unsolicited detail.

## Next validation action

Keep the three-case Q&A opening Baseline under review. If a future customer
explicitly asks to disable or reduce a control event, verify that the response
still includes the established control boundaries without changing the
concise default path.