Benchmark Almanac

Destructive actions (Anthropic)

Claude Opus 5.5 21% Only in system cards

Models continue real Claude Code transcripts cut just before a destructive action. Score is the rate of taking a destructive action.

Anthropic also reports how often models ask the user instead of acting. Tool results are simulated by another Claude model.

Made by Anthropic Deception and alignment Tasks kept private Last in a system card Sep 2026 Last model added Sep 2026
Level
Expert Specialists with years of training, often over hours of work
Scored
Graded by a model A language model scores each response, usually against a rubric.
Answers
Agent task Many steps in a terminal, browser, desktop, app, game or robot.
1
Model scored in lab cards
3
System cards report it, from 1 lab

Claude Opus 5.5 leads with 21%

Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.

  1. 1 Claude Opus 5.5 21%
#ModelScoreSettingDateSource
1 Claude Opus 5.5 21% Sep 2026 Model card

Scores over time

All the scores we have, one dot each, so a model tested at several settings appears more than once.

Reported by the lab in its model card
0% 20% 40% 60% 80% 100% Claude Opus 5.5 0% 20% 40% 60% 80% 100% Claude Opus 5.5

Labs report it only in system cards

We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark. Some system cards do, below.

3 system cards report it, from 1 lab

Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.

DateDocumentScoreAs the document writes itSection
22 Sep 2026 Claude Opus 5.5 system card 21 Destructive actions in Claude Code, destructive action rate when continuing real transcripts, lower is better (asked the user instead in 35%) (6.5.2, Figure 6.5.2.A) Alignment
16 Apr 2026 Claude Opus 4.7 system card Destructiveness evaluation by resampling Claude Code transcripts, clearly and borderline destructive rates on three prefill sources, chart without printed values (6.3.1.2, Figure 6.3.1.2.A) Alignment
7 Apr 2026 Claude Mythos Preview system card Destructive behavior rate when resampling Claude Code transcripts, Opus 4.6 and Mythos Preview prefills, clearly and borderline destructive, chart without printed values (4.3.1.2, Figure 4.3.1.2.A) Alignment

More in Safety and alignment

All 444 in Safety and alignment
  • FORTRESS In use Paired adversarial and benign national-security misuse prompts. Rubric-graded risk score on adversarial and over-refusal score on benign prompts. Claude Opus 5.5 5.78%
  • StrongREJECT In use Forbidden-prompt jailbreak benchmark with a rubric grader that scores how useful a non-refusal actually is. Inkling 98.6%
  • AgentDojo In use Agents do tool-use tasks while tools and data carry prompt injections. Attack success rate counts hijacked runs. Grok 4 Fast 0%
  • MASK In use Measures whether a model contradicts its own elicited beliefs under pressure to lie. Honesty separated from accuracy. Muse Spark Open 98.1%
  • Gray Swan IPI Arena benchmark In use Indirect prompt-injection attacks from public red-teaming competitions replayed on tool, coding and browser agents. Attack success rate at k attempts. GPT-6 Astra 8.50%
  • Agentic misalignment suite (Anthropic) In use Agents in simulated company settings face threats or goal conflicts that invite blackmail, leaking or sabotage. Score is the misaligned action rate. Claude Sonnet 4.5 0%