description: Matt Pocock-style interrogation of a product plan against the product canon (Torres, Cagan Transformed, Reinertsen/WSJF, Amplitude North Star, evals-as-PRD). One forcing question per turn with a recommended answer; refuses to invoke any sub-skill or start a loop until the outcome-defining decisions are locked. Use before running /cs:product or /cs:product-loop on a fuzzy plan.
argument-hint: "<product plan, roadmap, feature idea, or strategy to interrogate>"
/cs:grill-product — grill a product plan before running it
Interrogate this plan — do not execute anything yet:
$ARGUMENTS
Five rules (preserved from Matt Pocock, MIT): one question per turn · always give a
recommended answer · explore the workspace before asking · walk the decision tree
depth-first · track answered questions and their dependencies.
Decision tree
- Branch 1 — Outcome: "What single measurable outcome does this serve, with a number?
Recommended: write it as the OST root before anything else. Canon: Torres,
Continuous Discovery Habits."
- Branch 2 — Evidence: "Which tested assumption says this will work — and how many
independent participants back it? Recommended: link the surviving assumption test;
singletons are anecdotes. Canon: Bland, Testing Business Ideas; Torres."
- Branch 3 — Structure: "Does the tree pass the linter? Recommended: run
ost_linter.py — exit 0 before any roadmap cites it; feature-phrased opportunities
(O2) and untested solutions (O4) are the usual failures. Canon: Torres OST discipline."
- Branch 4 — Prioritization honesty: "Would delaying any item a quarter erode its
value? Recommended: if yes, run WSJF/cost-of-delay next to RICE and flag rank flips on
one-step estimate changes. Canon: Reinertsen; the WSJF false-precision critique."
- Branch 5 — Measurement: "Is your North Star a leading value metric with an input
tree, or revenue/vanity? Recommended: leading value metric; funnel verdicts need
benchmark bands. Canon: Amplitude, The North Star Playbook; ProductLed benchmarks."
- Branch 6 — AI features: "If any feature is probabilistic: where is the eval —
golden set, rubric, guardrail SLOs? Recommended: write the eval spec into the PRD
before building; vibe-check launches are shipping without tests. Canon: evals-as-PRD
(Lenny's/Braintrust)."
Per-turn output format:
Q[i]/[total]: [precise question]
Recommended: [answer + canon-cited rationale]
(Confirm, or override?)
Stop conditions
- All branches resolved → invoke
/cs:product (question) or /cs:product-loop
(recurring discovery) with the locked decisions inlined.
- User says "stop grilling, just run it" → run with unresolved branches flagged in the
digest.
- Abandoned → save the partial grill to
product-grill-{timestamp}.md.
Distinct from
engineering/grill-me — generic plan interrogation. This grills against the product
canon./cs:product — routes; this refuses to route until decisions are locked.
