ScaffoldBench

RunSonnet 5.5repeat 2

Plan-execute-verify on Rebook onto the earliest available flight and settle the difference

claude-sonnet-5-5__plan-execute-verify__airline-medium__r2

Score

1.000

passed
design ran as designed
Cost
$0.077
Latency
26.4s
setup 0.0s, grading 0.0s
Turns
17
Tool calls
12
Subagents
0
Tokens in / out
55k / 2.3k
40,447 read from cache

Did the design run?

every check held
  • Run completed: heldharness.run-completedThe environment was built, the architecture returned and grading finished, none of them throwing.
  • No API failures: heldharness.apiNo model call failed at the API.
  • Every call ended: heldharness.calls-endedEvery call ended with a result, or was stopped by the run's own limits.
  • No harness tool denied: heldharness.harness-toolsThe sandbox guard never denied a harness tool, nor a tool the session itself offered.
  • Tool servers connected: heldharness.mcp-connectedEvery tool server the harness gave a call was connected when the session started.
  • No foreign tool servers: heldharness.mcp-hermeticNo call loaded a tool server the harness did not give it.
  • Builtin tools: heldharness.builtin-toolsA check recorded with the run.
  • Structured replies arrived: heldharness.structured-outputEvery call that asked for structured output and ran to the end got it.
  • No silent fallbacks: heldharness.not-degradedNo phase fell back on a default (an empty plan, a default winner) instead of its output.
  • The plan was a plan: heldplan-execute-verify.planThe planner’s reply was read through its schema and held at least one step.
  • Every verdict was read: heldplan-execute-verify.verdictsEvery review round ended with a verdict read from the schema reply, not a default.
  • The loop did what its verdicts said: heldplan-execute-verify.loopEvery verdict that called for a revision got one, and nothing was revised without such a verdict.
  • Each call was shown the right tools: heldplan-execute-verify.toolsThe planner was shown no tools, the verifier the read-only ones, and the executor and reviser the full toolset.

Phases

Plan: 0.0s to 8.2s, finished, 0 tool calls, $0.012
Execute: 8.2s to 20.9s, finished, 7 tool calls, $0.034
Verify: 20.9s to 26.4s, finished, 5 tool calls, $0.030

Drawn from the phase records: timing and cost per call, no tool calls or messages.

PhaseDurationCostTurnsToolsModel
Plan8.2s$0.01220claude-sonnet-5-5
Execute12.6s$0.03487claude-sonnet-5-5
Verify5.5s$0.03075claude-sonnet-5-5

The call-by-call replay is not published for this run. Traces are large, so the repository keeps 9 of this run set’s 900 and leaves the rest out; the score, phases and final answer on this page come from the committed run record.

Runs you can replay

Record this cell yourself: npm run bench -- run --strategies plan-execute-verify --tasks airline-medium --models claude-sonnet-5-5 --repeats 1

Score breakdown

  • passReservation moved to the earliest flight with an available seat, same cabin
    1.00weight 0.43

    booked on AA204, expected AA204

  • passExactly one fee, the fare difference for the flight actually booked
    1.00weight 0.43

    fare difference owed on the booked flight: 8000 cents

  • passExactly one economy seat moved from the old flight to the new one
    1.00weight 0.14

Penalties

No penalties were applied.

Scorer metadata

tool calls
12
failed tool calls
0
distinct tools
8

Final answer

Dana is now on AA204, which departs SFO at 9:05 on 2026-08-03. She is still in economy, and she owes $80.00 for the change.

  • Why this flight: UA88 at 6:15 is the earliest departure, but it has no economy seats left. AA918 at 7:30 is cancelled. AA204 at 9:05 is the earliest flight that is operating and has economy seats (4 left).
  • Change fee: $0. The economy change fee is $75, but it is waived for gold and platinum members, and Dana is gold.
  • Fare difference: $80.00, charged as one fare_difference ledger entry (L1). Her original AA210 economy fare was $310 and AA204 economy is $390. Fare rules say no tier is exempt from a fare difference.
  • Total charged: $80.00.

I only changed R2087.

Provenance of the numbers on this page

run set
scaffold-or-scale-v1
models
Haiku 4.5, Sonnet 5.5, Opus 5.5
effort
high
repeats
2
fixtures
replay
runs
900 / 900
strategy cost
$354.44
judge cost
$9.19
wall clock
9h 48m
git
fce5807b2d

Cost excludes judge calls, which are tracked separately so a scoring model never flatters or penalises an architecture. Every figure on this site is read from results/ at build time.