# Common Decision Discipline

Right-size, ground, and gate SDLC decisions with SNC-sized depth, said-vs-assumed...

- Repository: https://github.com/HoangNguyen0403/agent-skills-standard (582 stars)
- Category: Design
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add HoangNguyen0403/agent-skills-standard --skill common-decision-discipline -g -a claude-code -y`
Codex: `npx skills add HoangNguyen0403/agent-skills-standard --skill common-decision-discipline -g -a codex -y`
Cursor: `npx skills add HoangNguyen0403/agent-skills-standard --skill common-decision-discipline -g -a cursor -y`
Gemini CLI: `npx skills add HoangNguyen0403/agent-skills-standard --skill common-decision-discipline -g -a gemini-cli -y`

## 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.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# 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.
- Downward complexity reassessment requires documented new evidence (e.g., scouted blast radius proves isolated scope), never to bypass unresolved risk, required approvals, or the sensitive-change risk floor.
- **Sensitive-Change Risk Floor**: Auth, money, data integrity, or trust boundaries enforce minimum `tier=medium` regardless of arithmetic SNC total; non-zero novelty or spread (S≥1 or N≥1 with C=2) escalates to `tier=high`.
- **Low-Risk Maintenance**: Sufficiently specified routine fixes or maintenance may use an in-chat contract rather than creating BRD/PRD/SRS files. Preserve full traceability for governed or high-risk delivery.
- Downstream specialist workers execute against their assigned briefs; do not reload or repeat parent intake in specialists.
- A symptom without a root cause routes to `dev-fix`; never compare fixes for an undiagnosed bug.
## 2. Shared Understanding

The rest: https://github.com/HoangNguyen0403/agent-skills-standard/blob/HEAD/.agents/skills/common/common-decision-discipline/SKILL.md