msd-core/capabilities/live-dom-uat/fragments/execute-wave-post.md

Verify the live-DOM acceptance criteria for the execution wave that just completed. Answer: "of this wave's stated UI acceptance criteria, which can I observe in a live DOM right now, and which could I not look at?"

This step is ADDITIVE. It never halts the wave, never fails the phase, and never rewrites SUMMARY.md. If you cannot look, say so and finish.

<required_reading>

• {phase_dir}/{phase_num}-PLAN.md (the wave's tasks and their acceptance criteria)
• {phase_dir}/{phase_num}-UI-SPEC.md if it exists (the design contract, when the phase has one) </required_reading>

<browser_surface> You carry exactly two browser MCP families: mcp__chrome-devtools__* and mcp__claude-in-chrome__*. Use whichever responds. Do not assume they expose the same tool names — probe, then use what is there. Do not paper over differences between them.

You do NOT carry the Playwright MCP family. That path belongs to the orchestrator's own verification step and is not yours. </browser_surface>

<profile_lock> chrome-devtools-mcp holds an exclusive lock on its browser profile ($HOME/.cache/chrome-devtools-mcp/chrome-profile). A second concurrent instance fails with:

The browser is already running for <dir>. Use --isolated to run multiple browser instances.

If you see that, or any equivalent lock error:

1. Record outcome: could_not_look and reason: profile_locked.
2. Name --isolated in the notes, so the operator knows the remedy is a flag on THEIR MCP server registration.
3. Stop. Do not retry, do not loop, do not wait for the lock. GSD cannot pass --isolated — it is not GSD's flag — and a retry loop here just holds up the wave.

Parallel execution waves sharing one profile WILL hit this. It is an expected condition, not a defect, and it is not a reason to fail anything. </profile_lock>

For each UI acceptance criterion you can identify in the wave's plan:

1. Resolve its target URL. If no dev server or target is reachable, that criterion is could_not_look / target_unreachable — not a failure.
2. Open it with the browser family that responded.
3. Observe the DOM for the specific, stated condition. Assert on structure and content — an element's presence, its text, its attributes, its computed state.
4. Record passed when the stated condition is observably true, needs_review when it is ambiguous or requires human judgement (subjective aesthetics, content accuracy).

Scope limit for this version: DOM observation against stated criteria only. No screenshot diffing, no accessibility audit, no performance tracing. If a criterion needs one of those, mark it needs_review and say which.

Never invent a criterion. If the plan states no UI acceptance criteria, that is outcome: nothing_to_report / reason: no_criteria, and it is a perfectly good result.

Write to: {phase_dir}/{phase_num}-DOM-VERIFY.md

Frontmatter carries scalars only, so a reader can get the verdict without parsing prose:

---
schema_version: 1
wave: {wave_number}
outcome: verified | nothing_to_report | could_not_look
reason: ok | no_criteria | no_browser_mcp | profile_locked | target_unreachable
checked: <integer>
passed: <integer>
needs_review: <integer>
---

Then a short body: one line per criterion with its verdict, and — when outcome is could_not_look — exactly what stopped you and what the operator would change.

nothing_to_report and could_not_look are different outcomes and must never be conflated. "There were no UI criteria in this wave" and "there were criteria but I had no browser" look identical in a summary that collapses them, and that ambiguity is the reported problem this capability exists to remove.