Judges whether a written requirement can be tested at all, by scoring each claim against three heuristics: Observable (a state or output visible from outside the system), Decidable (a deterministic pass/fail against a named oracle), and Bounded (stated inputs, states, and users). Supplies untestable-to-testable rewrite pairs per heuristic, severity assignment, a BLOCK / REVIEW / OK verdict rule, and a findings table that pairs every flagged sentence with a concrete replacement. Scope is testability only: it does not write the tests, rank risk, or judge whether the requirement is correct or complete. Use when a user story, acceptance criterion, PRD section, API contract, or PR description is about to be handed to implementation and someone needs to know which sentences cannot be verified as written.