ScaffoldBench

RunOpus 5.5repeat 1

Plan-execute on Run the major-incident runbook for a CI outage

claude-opus-5-5__plan-execute__support-major-incident__r1

Score

0.880

wrong answer
design ran as designed
Cost
$0.374
Latency
2m 45s
setup 0.0s, grading 0.0s
Turns
52
Tool calls
49
Subagents
0
Tokens in / out
306k / 8.6k
285,519 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.planThe planner’s reply was read through its schema and held at least one step.
  • Each call was shown the right tools: heldplan-execute.toolsThe planner was shown no tools and the executor the task’s full toolset.

Phases

Plan: 0.0s to 20.9s, finished, 0 tool calls, $0.045
Execute: 20.9s to 2m 45s, finished, 49 tool calls, $0.329

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

PhaseDurationCostTurnsToolsModel
Plan20.9s$0.04520claude-opus-5-5
Execute2m 24s$0.3295049claude-opus-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 --tasks support-major-incident --models claude-opus-5-5 --repeats 1

Score breakdown

  • passAn incident is open for the build pipeline
    1.00weight 0.04
  • passThe incident-command engineer on call now commands the incident
    1.00weight 0.08

    commander=E-401 (expected E-401)

  • passThe commander was paged
    1.00weight 0.04
  • passT-3101 linked to the incident
    1.00weight 0.04
  • passT-3101 kept open, raised to sev1 with its deadline intact
    1.00weight 0.02

    status=open severity=sev1 due=2026-03-30T18:52:00Z (expected sev1, 2026-03-30T18:52:00Z)

  • passT-3102 linked to the incident
    1.00weight 0.04
  • passT-3102 kept open, raised to sev1 with its deadline intact
    1.00weight 0.02

    status=open severity=sev1 due=2026-03-30T18:58:00Z (expected sev1, 2026-03-30T18:58:00Z)

  • passT-3103 linked to the incident
    1.00weight 0.04
  • passT-3103 kept open, raised to sev1 with its deadline intact
    1.00weight 0.02

    status=open severity=sev1 due=2026-03-30T19:01:00Z (expected sev1, 2026-03-30T19:01:00Z)

  • passT-3104 linked to the incident
    1.00weight 0.04
  • passT-3104 kept open, raised to sev1 with its deadline intact
    1.00weight 0.02

    status=open severity=sev1 due=2026-03-31T15:05:00Z (expected sev1, 2026-03-31T15:05:00Z)

  • passT-3105 linked to the incident
    1.00weight 0.04
  • passT-3105 kept open, raised to sev1 with its deadline intact
    1.00weight 0.02

    status=open severity=sev1 due=2026-04-01T15:07:00Z (expected sev1, 2026-04-01T15:07:00Z)

  • passT-3106 linked to the incident
    1.00weight 0.04
  • passT-3106 kept open, raised to sev1 with its deadline intact
    1.00weight 0.02

    status=new severity=sev1 due=2026-03-30T16:20:00Z (expected sev1, 2026-03-30T16:20:00Z)

  • passT-3109 linked to the incident
    1.00weight 0.04
  • passT-3109 kept open, raised to sev1 with its deadline intact
    1.00weight 0.02

    status=new severity=sev1 due=2026-03-30T16:20:00Z (expected sev1, 2026-03-30T16:20:00Z)

  • passT-3112 linked to the incident
    1.00weight 0.04
  • passT-3112 kept open, raised to sev1 with its deadline intact
    1.00weight 0.02

    status=new severity=sev1 due=2026-03-30T16:20:00Z (expected sev1, 2026-03-30T16:20:00Z)

  • failT-3113 linked to the incident
    0.00weight 0.04
  • failT-3113 kept open, raised to sev1 with its deadline intact
    0.00weight 0.02

    status=open severity=sev3 due=2026-03-31T15:13:00Z (expected sev1, 2026-03-31T15:13:00Z)

  • failT-3114 linked to the incident
    0.00weight 0.04
  • failT-3114 kept open, raised to sev1 with its deadline intact
    0.00weight 0.02

    status=open severity=sev3 due=2026-03-31T15:16:00Z (expected sev1, 2026-03-31T15:16:00Z)

  • passThe engineer covering comms right now is the communications lead
    1.00weight 0.08

    comms=E-803 (expected E-803)

  • passA status update in the runbook form, with the next update due within 30 minutes
    1.00weight 0.08
  • passA postmortem ticket for the service, linked to the incident, due at close of business five business days on
    1.00weight 0.08

    T-3115 due=2026-04-08T17:00:00Z

Penalties

No penalties were applied.

Scorer metadata

tool calls
49
failed tool calls
0
distinct tools
18

Final answer

I've run the company-wide CI outage as major incident INC-1, following the current runbook (KB-40). KB-39 is marked as superseded by KB-40, so I didn't use it. One thing to know first: the desk clock reads 2026-03-30 15:20 UTC, not 2026-10-06, so every time and on-call lookup is based on 30 March.

What I did, in runbook order:

  1. Opened INC-1 for build-pipeline at 15:20, before contacting anyone.
  2. Paged Priya Raman (E-401) once, the only page sent, and made her incident commander. She is on the incident-command rotation right now and isn't on leave. As the runbook requires, I picked her by who is on call now, not by any ticket deadline.
  3. Linked the 8 outage reports to INC-1: T-3101, T-3102, T-3103, T-3104, T-3105, T-3106, T-3109 and T-3112. T-3112 ("Deploy jobs failing everywhere") came in while I was working and has the same cause: jobs waiting for a runner.
  4. Raised all 8 to sev1 and kept the deadlines already committed on them. T-3106, T-3109 and T-3112 had no deadline, so each now has one at triage time plus the 60-minute sev1 target: 16:20 UTC.
  5. Named Elif Demir (E-803) comms lead. Mia Laurent (E-801), who is rostered on comms, is on sick leave until 31 March, so the backup rotation (comms-secondary) covers, and Elif is on call there now.
  6. Posted the first status update: "Impact: All CI builds company-wide are failing; no build runners are picking up jobs in any pool. Started: 14:52 UTC. Next update: 15:50 UTC." 14:52 is when the first report came in.
  7. Opened postmortem ticket T-3115, linked to INC-1, due 8 April 17:00 UTC. That is close of business on the 5th business day; 3 and 6 April are company holidays.

Where I departed from the plan:

  • I merged nothing. The runbook governs the incident, and it says to link every open report and raise each one to sev1, not merge them. Merging would close all but one report and lose the separate deadlines committed to each requester. I didn't assign or escalate anyone either, because the runbook allows only one page (Priya's). T-3101 stays with Dana Whitfield (E-101).
  • Two tickets were left alone because they are separate problems. T-3107 (flaky payments-service test) is a known separate issue (KB-41), and T-3108 (local build failing after an Xcode upgrade) doesn't involve CI (KB-42). T-3108 is still untriaged, and the handbook says to change only the tickets the request is about.
  • Nothing else needed handling. There were no security reports or spam in the queue, so I closed nothing. No knowledge-base article amends the severity matrix.

Still waiting:

  • The next status update is due at 15:50 UTC.
  • T-3106, T-3109 and T-3112 are due at 16:20 UTC and still have no assignee.
  • The incident-command shift changes at 16:00, when Ola Berg (E-402) takes over from Priya.

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.