Right-size, ground, and gate SDLC decisions with SNC-sized depth, said-vs-assumed write-back, an evidence ledger, honest option cards, recorded approval, and self-review. Use when running brainstorm-feature, plan-feature, design-solution, or system-design-session.
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---
name: common-decision-discipline
description: Right-size, ground, and gate SDLC decisions with SNC-sized depth, said-vs-assumed write-back, an evidence ledger, honest option cards, recorded approval, and self-review. Use when running brainstorm-feature, plan-feature, design-solution, or system-design-session.
guardrail: true
metadata:
triggers:
files: []
keywords:
- decision brief
- delivery contract
- compare approaches
- evidence ledger
- approval state
- option trade-offs
- shape a direction
---
# Decision Discipline
## **Priority: P0 (CRITICAL)**
Trustworthy decisions are sized to the work, grounded in evidence, and approved on the record.
## 1. Size The Work
| SNC tier | Depth | Artifact |
| --- | --- | --- |
| `tier=low` (0-2) | Quick | Contract in chat, no file; `approval` in the Handoff Payload |
| `tier=medium` (3-4) | Standard | Core brief file |
| `tier=high` (5-6) | Deep | Full brief; decompose multi-subsystem ideas first; optional `specialist-architecture-guard` review |
- Score with `common-task-complexity-routing`; label as inference until scouted. The tier only rises once work starts.
- A symptom without a root cause routes to `dev-fix`; never compare fixes for an undiagnosed bug.
## 2. Shared Understanding
- Draft first, then write back two lists: **You said** and **I assumed**. Allow one correction round.
- Skip the write-back when outcome, constraints, non-goals, and acceptance criteria are already stated; confirm in one line.
- Reuse an accepted contract; never reopen it.
## 3. Evidence Ledger
- Tag every feasibility, AS-IS, or current-behavior claim: `confirmed(<path>)`, `assumed`, or `unknown`.
- Read the smallest useful set of code, tests, docs, and existing `docs/brd|prd|srs` before calling an option feasible.
- Resolve what evidence can settle; label only what stays unknowable. Format: `references/evidence-ledger.md`.
## 4. Questions
- Ask only when the answer changes the result, safety boundary, or public contract.
- Max 3 per round, each with a recommended default and 2-3 options.
- Never re-ask a settled fact. Never ask the operator to re-authorize approved work.
- For `operator_profile=business`, every question is answerable by "go with your suggestion".
## 5. Options
- 0-3 options, only when a real choice exists. A single viable path is stated as the path, not padded.
- Each option card names its load-bearing assumption, first failure condition, worst plausible case, and cost to abandon (`references/option-card.md`).
- Recommend the smallest option that satisfies the contract. When a critical assumption is unresolved, recommend the option cheapest to abandon.
- Cut unrequested scope; keep all requested scope.
## 6. Approval State
- `approval: pending | approved(<who>, <YYYY-MM-DD>) | assumed-autonomous`.
- Interactive: end with "Reply ok or corrections". An ok approves only the artifact presented.
- Autonomous or channel mode without an interactive reply channel: set `assumed-autonomous` and continue; `tier=high` still blocks pending explicit human sign-off.
## 7. Self-Review Before Handoff
- Placeholders: TBD, TODO, empty sections.
- Contradictions between sections.
- Scope: one plan, or needs splitting.
- Ambiguity: a requirement with two readings; pick one and state it.
## Red Flags
Stop when thinking: "too simple to need a brief", "they said implement, so skip intake", "it's a bug, pick a fix", "list three options to look thorough", "ask again to be safe", "they approved the idea, so the plan is approved". Each is a rationalization, not a reason.
## Anti-Patterns
- **No unlabeled claims**: every AS-IS or feasibility statement carries an evidence tag.
- **No padded options**: never invent alternatives to reach three.
- **No silent approval**: a brief without `approval` is incomplete.
- **No reopened decisions**: settled facts are carried forward, not re-asked.
## References
- [Contract Templates](references/contract-template.md)
- [Evidence Ledger](references/evidence-ledger.md)
- [Option Card](references/option-card.md)
