SSPEC: Reading the ask-or-proceed decision off the declared interface of an agent tool call

On a published travel-planning agent, 0.8963 of call arguments are not written by the executor itself, yet actions that cannot be undone consume them. However, ask-or-proceed instruments question the executor at the step that writes a value, and the executor reports only what it knew it chose. We propose Schema-Sourced Specification (SSPEC), a framework that reads the ask-or-proceed decision off the declared interface. A recovery operator enumerates the fields a call puts in force from the declared schema and returns those no witness in the evidence buffer carries. An exposure split defers the question on each such value to the first unrevertable dispatch that consumes it. Budgeted selection spends an interruption allowance on the groups of fields that one declared unit or frame parameter closes. The key insight is that the interface already carries what the executor cannot report: the schema lists the values in force, and the dispatch fixes when each one matters. SSPEC reads 92.60% API match rate on default-filled-only episodes against 83.70% for the strongest published predictor and recovers 68.4% of the unsupported values there against 38.6% for executor self-report. On ProClare it asks 1.6657 questions per episode against 5.0000 for an every-turn rule and completes 49.5000% of tasks against 47.0000% for the strongest published policy. On the Minecraft Dialogue Corpus, withdrawing the exposure split raises irreversible exposure from 8.6100% to 17.2500% at an almost unchanged question count, and withdrawing budgeted selection raises questions from 0.9320 to 1.1890 at an almost unchanged exposure; the two costs are charged at different places.