9.7Anti-Patterns to Avoid

Don't: Use MCP for Every Click When You Have a Filesystem

# BAD: Each action via MCP from inside Claude Code
browser_click(ref=e5)      # tree streamed with the response
browser_type(ref=e3, "hi") # tree streamed again
browser_click(ref=e7)      # and again
# Schemas every turn + a tree per action, for no benefit

Don't: Act on Guessed or Stale Refs

# BAD: refs from a page that has since changed
playwright-cli click e5      # ref belonged to the old snapshot
playwright-cli click e12     # guessing
# Wasted attempts + error handling

# GOOD: refs always come from a current snapshot
playwright-cli snapshot      # refresh
# read YAML → button "Submit" [ref=e9]
playwright-cli click e9

Do: Match the Transport to the Environment

# GOOD
Filesystem available (Claude Code, CI)  → playwright-cli + SKILL.md
No filesystem (hosted/sandboxed agent)  → Playwright MCP
Both needed on one browser              → browser.bind() shares the instance