SKILL.md
$27
screenshot (snapshot)
playwright: await ref('e3').fill('Jane')
screenshot (snapshot) ← WHY? page didn't change
playwright: await ref('e5').fill('jane@example.com')
playwright: await ref('e7').click()GOOD — 2 tool calls:
screenshot (snapshot)
playwright (snapshotAfter=true):
await ref('e3').fill('Jane');
await ref('e5').fill('jane@example.com');
await ref('e7').click();
return { title: await page.title(), url: page.url(), errors: (await page.$$('.error')).length };Use return to collect data. Response: { result: <value>, resultFile: "<tmp path>", snapshot: { tree, refs, stats } }. The resultFile persists until close — read or grep it later. Without a return value, responds "OK" (or just the snapshot if snapshotAfter=true).
Re-snapshot only across DOM boundaries. Fills and hovers don't change page structure — keep using the same refs. Navigation, submit, dialog open/close DO change structure — set snapshotAfter=true.
Writing Instructions
Bad: "Check that the login form renders on http://localhost:5173"
Good: "Submit the login form empty, with invalid email, with wrong password, and with valid credentials. Verify error messages, redirect on success, and console errors on http://localhost:5173"
Before Claiming Completion
- Verify in a browser with adversarial instructions.
- Read the full output — check failures, accessibility, performance.
- If ANY failure: fix the code, re-verify immediately. No asking, no waiting.
- Repeat until 0 failures, then state the claim with passing evidence.
Rationalizations
- "I'll run the browser test inline, it's quick" — Probably not. Launch a subagent so you can keep editing code in parallel. Only skip the subagent for a single screenshot sanity check.
- "I'll open a fresh browser to re-test" — Check for an existing session first. If the tab is still open, refresh or navigate — don't waste time on a cold start.
- "I'll make one
playwrightcall per action" — No. Whole sequence in one call.
- "I need a snapshot between fills" — No. Fills don't change DOM. Batch them.
- "Let me snapshot to see what changed" — Did the page navigate or submit? No? Use
snapshotAfter=trueon the action that does.