The Visible Test Suite Is the Ceiling on What the Next Agent Can Deliver

Two 2026 verification-horizon papers land the same measurement: coding agents saturate whatever suite they can see, and the gap between visible pass and actually correct widens with task complexity. The visible test suite is a ceiling on what a search process can converge toward on the codebase it operates against. Waiting for a stronger model moves the agent under the same ceiling faster; it does not raise it. The lever that raises the ceiling is a suite whose discrimination power outruns the search it is trying to guide.