mcaf-adr-writing

A guide for writing an Architecture Decision Record, or ADR: a short document that records an important technical choice and why it was made.

In plain words
What is it for?
Use it to create or update ADRs under docs/ADR/ and document alternatives, trade-offs, risks, and the selected architecture decision.
Why use it?
It preserves the reasoning behind changes to dependencies, system boundaries, data models, or shared engineering policies so later work is less ambiguous.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/managedcode/dotpilot/mcaf-adr-writing
Any agent
npx skills add managedcode/dotPilot --skill mcaf-adr-writing
Clone the repo
git clone --depth 1 https://github.com/managedcode/dotPilot

Made for: Claude Code, Codex.

Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 854 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00069 $0.00854
Opus 5 $0.00034 $0.00427
Sonnet 5 $0.00014 $0.00171
Haiku 4.5 $0.00007 $0.00085

Measured 2d ago against content hash e76bc9c70a8b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcaf-adr-writing scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to mcaf-adr-writing — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.codex/skills/mcaf-adr-writing/SKILL.md · 104 lines

How it starts

The opening of the file, as written. The whole thing — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCAF: ADR Writing

Trigger On

  • a dependency, boundary, platform, contract, or data model is changing
  • a design decision has meaningful trade-offs that should be recorded
  • a repo-wide engineering policy needs a durable rationale

Value

  • produce a concrete project delta: code, docs, config, tests, CI, or review artifact
  • reduce ambiguity through explicit planning, verification, and final validation skills
  • leave reusable project context so future tasks are faster and safer

Do Not Use For

  • feature-level behaviour details without an architecture decision
  • generic architecture overview content

Inputs

  • docs/Architecture.md
  • related feature docs
  • the nearest AGENTS.md
  • current constraints, options, and risks

Quick Start

  1. Read the nearest AGENTS.md and confirm scope and constraints.
  2. Run this skill's Workflow through the Ralph Loop until outcomes are acceptable.
  3. Return the Required Result Format with concrete artifacts and verification evidence.

Workflow

  1. Start from the concrete decision that must be made now.
  2. If the ADR is missing, scaffold it from references/adr-template.md.
  3. Record:
    • context and problem
    • chosen decision
    • alternatives considered
    • trade-offs and consequences
    • implementation plan
  4. Add diagrams only when they remove ambiguity.
  5. Link the ADR to affected feature docs and docs/Architecture.md.

Deliver

  • docs/ADR/ADR-XXXX-short-title.md
  • linked updates to architecture docs when the decision changes boundaries

Validate

  • the decision and rejected alternatives are explicit
  • trade-offs are concrete, not hand-wavy
  • implementation impact is clear
  • a future engineer can understand why this path was chosen

Ralph Loop

Use the Ralph Loop for every task, including docs, architecture, testing, and tooling work.

  1. Brainstorm first (mandatory):
    • analyze current state
    • define the problem, target outcome, constraints, and risks
    • generate options and think through trade-offs before committing
    • capture the recommended direction and open questions
  2. Plan second (mandatory):
    • write a detailed execution plan from the chosen direction
    • list final validation skills to run at the end, with order and reason
  3. Execute one planned step and produce a concrete delta.
  4. Review the result and capture findings with actionable next fixes.
  5. Apply fixes in small batches and rerun the relevant checks or review steps.
  6. Update the plan after each iteration.
  7. Repeat until outcomes are acceptable or only explicit exceptions remain.
  8. If a dependency is missing, bootstrap it or return status: not_applicable with explicit reason and fallback path.

Read the full file on GitHub · 104 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 104 lines · 69 tokens per session scan A e76bc9c70a8b

Subscribe to this mod's changes

mcaf-adr-writing is a skill published in the GitHub repository managedcode/dotPilot (23 stars, last pushed 4mo ago), licensed MIT. It adds 69 tokens to every session and 854 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to mcaf-adr-writing, differing in 0 lines, and is treated as a copy.