code-review-change-size

Code-review guidance for keeping software changes small enough to inspect. It sets lower limits for complex logic and asks for larger work to be split into reviewable stages.

In plain words
What is it for?
Use it when preparing a code change for review. It helps decide whether to split a change and which smallest stage should be delivered first, based on the actual code affected.
Why use it?
Large changes are harder to understand and more likely to hide mistakes. The guidance helps reviewers focus on one coherent piece at a time.

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/openai/codex/code-review-change-size
Any agent
npx skills add openai/codex --skill code-review-change-size
Clone the repo
git clone --depth 1 https://github.com/openai/codex

Made for: Claude Code, Codex.

Per session 12 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 91 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00012 $0.00091
Opus 5 $0.00006 $0.00046
Sonnet 5 $0.00002 $0.00018
Haiku 4.5 $0.00001 $0.00009

Measured 3d ago against content hash e8184218e0f0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

code-review-change-size 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 3d 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

Copies of this mod

7 near-identical copies found in the catalogue:

.codex/skills/code-review-change-size/SKILL.md · 12 lines

What it actually says

Unless the change is mechanical the total number of changed lines should not exceed 800 lines. For complex logic changes the size should be under 500 lines.

If the change is larger, explain whether it can be split into reviewable stages and identify the smallest coherent stage to land first. Base the staging suggestion on the actual diff, dependencies, and affected call sites.

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. 3d ago First seen · 12 lines · 12 tokens per session scan A e8184218e0f0

Subscribe to this mod's changes

code-review-change-size is a skill published in the GitHub repository openai/codex (120,598 stars, last pushed yesterday), licensed Apache-2.0. It adds 12 tokens to every session and 91 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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