Grill is the first stage and the one place the pipeline is allowed to interrupt the person who started it. Its contract is a single batched round of questions that turns a casual or fuzzy request into something buildable, and that round is where all user decisions happen, including any judgment call a later stage would otherwise stop to ask about. If the task lands in territory the user does not know well, a blindspot pass runs first so the round can ask the right questions.

open ⤢
Ground first, then one batched round of at most three questions. Every decision a later stage would need is settled here, so the pipeline can run without stopping.

The stage exists to pin the specification once. Out of it comes a scoped work unit or a committed spec that every downstream stage treats as the authority. The reason to concentrate every question here is what it buys afterwards: across the whole run the user is interrupted at most twice, at this round and at the final handoff, and everything between runs without stopping. A stage that pauses to ask "looks good?" has failed the contract. Pin the spec once, then run.