9.6Implementation: A Simple Hybrid Test

Here's what the working rhythm looks like in practice, as an agent would execute it:

Agent thinking: "I need to test the login flow on the redesigned page.
I don't know the new structure. Snapshot first."

Step 1: Navigate (cheap)
  → Bash: playwright-cli open https://app.example.com/login

Step 2: Discover page structure (one disk read)
  → Bash: playwright-cli snapshot     → .playwright-cli/ YAML path
  → Agent reads:
    - form "Login":
      - textbox "Email address" [ref=e3]
      - textbox "Password" [ref=e4]
      - button "Sign in" [ref=e5]
      - link "Forgot password?" [ref=e6]

Step 3: Execute test (refs — cheap)
  → Bash: playwright-cli fill e3 "test@example.com"
  → Bash: playwright-cli fill e4 "secret"
  → Bash: playwright-cli click e5

Step 4: Verify (one more snapshot read)
  → Bash: playwright-cli snapshot
  → Agent reads: heading "Dashboard", text "Welcome, Test User"

Step 5: Evidence (file path only — image never enters context)
  → Bash: playwright-cli screenshot

Total: 2 snapshot reads (~4K tokens) + 6 commands (~400 tokens) ≈ 4,500 tokens
vs. Pure MCP for the same flow: ~25,000-35,000 tokens