Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Reach a goal stack configuration using a simulator CLI with minimal moves

AClaude Opus 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-16 · by @bobsiopener

Trust 80%Fully autonomoussuccess · first tryCompare

Estimated cost: $0.11
Wall time: 17s
Human step-ins: 0
Outcome: Pass

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Exact prompt

# Task: plan with a tool `wh.py` is a warehouse stacking simulator (read its docstring: `python wh.py status`). Reach the goal configuration in `goal.json` using ONLY `python wh.py move SRC DST` calls. Every call (including `status` and rejected moves) is logged in `calls.log`; your score depends on reaching the goal with as few `move` calls as possible (rejected moves count). Do NOT edit `wh.py`, `state.json`, `goal.json`, or `calls.log` by hand — the grader replays `calls.log` from the initial state. Plan before moving. No network.

Grader replays calls.log; optimal is 13 moves (BFS), pass ≤15 with zero rejected moves. Rewards planning before acting over trial-and-error. Original benchmark task written for usecaserank.com (not based on a specific public post). Headless, offline run on a reproducible fixture. Each run's notes say how its cost was measured (estimates are marked).

Success criteria: 1. wh.py and goal.json must be unmodified. 2. Replaying calls.log from the original initial state must reach the goal configuration. 3. Zero rejected (illegal) moves in the log. 4. Number of move calls <= optimal (computed by BFS in the scorer) + 2.

Setup notes: Use Case Scout batch 4 case d11-tool-use-planning (offline fixture). Prepared with batch4/prepare.sh; hidden key/tests kept outside the agent's work dir. Prompt = TASK.md verbatim. Scored with the scout's scorer: `python score.py WORKDIR`. Tools: Read/Write/Edit/Glob/Grep/Bash, web disabled. Single run, no retries. Claude Code's own reported cost for claude-opus-5.5: $0.110012. Score: 4/4 checks. Cost is an ESTIMATE: measured tokens x pricing.json list price (Claude Pro subscription, nothing billed); input_tokens include cache reads and writes. Single run.

Estimated cost List-price estimate; not actually billed.

Metrics

Estimated cost: $0.11
Wall time: 17s
Human step-ins: 0
Turns: 5

Model usage
Model	Input tok	Output tok	Cost
AClaude Opus 5.5anthropic/claude-opus-5.5effort default (no --effort flag) · thinking on	95,260	1,492	$0.11

Reproduce this run

Use the use case prompt on the use case page.
Same setup: Claude Opus 5.5 (anthropic/claude-opus-5.5, effort default (no --effort flag) · thinking on) via Claude Code 2.1.299 (headless -p), cloud.
It counts as a success only if it meets every success criterion: 1. wh.py and goal.json must be unmodified. 2. Replaying calls.log from the original initial state must reach the goal configuration. 3. Zero rejected (illegal) moves in the log. 4. Number of move calls <= optimal (computed by BFS in the scorer) + 2.
Log model, tokens, wall time, human step-ins and the evidence log, then submit it as a reproduction. A different model? Submit a head-to-head rerun.

How runs are scored: Methodology.

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Automated checks

Trust 80% comes from these checks (how Trust % works).

Run date is not in the future : passed
Model is in the dated pricing table : passed
Cost recomputed from tokens matches : passed
Cached tokens are consistent : passed
Output throughput is plausible : passed
Autonomy matches step-ins : passed
Step-ins do not exceed turns : passed
Retries agree with first-try result : passed
Evidence log SHA-256 matches : passed
Evidence log is substantial : passed

Evidence log

[
 {
  "duration_api_ms": 15375,
  "stop_reason": "end_turn",
  "session_id": "[REDACTED]",
  "total_cost_usd": 0.1100118,
  "usage": {
   "input_tokens": 10,
   "cache_creation_input_tokens": 7831,
   "cache_read_input_tokens": 87419,
   "output_tokens": 1492,
   "output_tokens_details": {
    "thinking_tokens": 102
   },
   "server_tool_use": {
    "web_search_requests": 0,
    "web_fetch_requests": 0
   },
   "service_tier": "standard",
   "cache_creation": {
    "ephemeral_1h_input_tokens": 7831,
    "ephemeral_5m_input_tokens": 0
   },
   "inference_geo": "global",
   "iterations": [
    {
     "input_tokens": 2,
     "output_tokens": 370,
     "cache_read_input_tokens": 19647,
     "cache_creation_input_tokens": 330,
     "cache_creation": {
      "ephemeral_5m_input_tokens": 0,
      "ephemeral_1h_input_tokens": 330
     },
     "type": "message"
    }
   ],
   "speed": "standard",
   "fallback_credit": null
  },
  "modelUsage": {
   "claude-opus-5-5": {
    "inputTokens": 10,
    "outputTokens": 1492,
    "cacheReadInputTokens": 87419,
    "cacheCreationInputTokens": 7831,
    "webSearchRequests": 0,
    "costUSD": 0.1100118,
    "contextWindow": 1000000,
    "maxOutputTokens": 128000,
    "thinkingTokens": 102,
    "canonicalModel": "claude-opus-5-5",
    "provider": "firstParty",
    "costBasis": "list"
   }
  },
  "permission_denials": [],
  "terminal_reason": "completed",
  "fast_mode_state": "off",
  "fast_mode_disabled_reason": "sdk_opt_in_required",
  "subagent_stats": {
   "spawned": 0,
   "requested": {
    "background": 0,
    "foreground": 0,
    "unset": 0
   },
   "started_in_background": 0,
   "max_depth": 0,
   "spawned_by_subagents": 0,
   "completed": 0,
   "failed": 0,
   "killed": {
    "parent": 0,
    "user": 0,
    "system": 0
   },
   "refused": {
    "depth_limit": 0,
    "concurrency_limit": 0,
    "budget": 0
   },
   "by_type": {}
  },
  "safety_stops": 0,
  "is_error": false,
  "num_turns": 5,
  "subtype": "success",
  "api_error_status": null,
  "result": "The warehouse now matches `goal.json` exactly, in 13 moves with none rejected. A search over every reachable state showed 13 is the fewest possible.\n\n- **Final state:** A is empty, B holds a b f d e (bottom to top), C holds c, and the dock D is empty.\n- **Moves made:** B\u2192C, A\u2192C, B\u2192D, A\u2192D, A\u2192B, D\u2192A, C\u2192A, D\u2192B, C\u2192D, C\u2192B, D\u2192B, A\u2192B, A\u2192C.\n- **`calls.log`:** it has exactly those 13 move lines. I worked out the plan by reading `wh.py` and the JSON files directly, so I never ran `status` and nothing extra was logged.\n\nThere's no `python` command on this machine, so I ran `python3 wh.py move ...` instead. The first attempt with `python` failed before the script started, so it logged nothing and changed nothing. The log stores only the arguments, so it replays the same way with either interpreter.\n\nThe planning script is at `/tmp/plan/bfs.py`, outside the work folder.",
  "ttft_ms": 1691,
  "type": "result",
  "duration_ms": 16026,
  "uuid": "[REDACTED]",
  "ttft_stream_ms": 860,
  "time_to_request_ms": 240,
  "first_content_frame_ms": 861,
  "queued_turn_count": 0,
  "result_index": 0
 }
]