The scenario
The UI changes immediately. Persistence after a successful save is required, and a failed save must not be presented as confirmed.
Required context: a selected repository matching this scenario, relevant task evidence, and access to its instructions and checks. Use redacted or synthetic data where appropriate.
Adapt the complete prompt
Edits stay in this browser tab. Saving bookmarks the original example; export your edited version to keep it elsewhere.
Why this is a strong example
It separates optimistic UI state from confirmed persistence and includes the failed-save case.
A concrete outcome
Fix the preference toggle that appears saved but resets after a page reload.
The result can be assessed against an observable task rather than prompt length or confidence.
Boundaries and a method
Trace the save and initial-load paths before editing. Preserve the current storage and authentication architecture and existing unrelated preferences.
This leaves implementation judgment while constraining the changes that would exceed the task.
Evidence that can disagree
Exercise save, reload, failure and retry. Inspect the request and response evidence and the resulting stored value without logging private data.
These checks describe what would make acceptance justified; asking for them does not mean they ran.
A safe way to encounter uncertainty
If the repository contradicts these assumptions, required access is unavailable, or a consequential product decision is missing, explain the conflict and pause the dependent work. Preserve unrelated changes.
Consequential uncertainty stays visible rather than being converted into an invented requirement.