code-simplifier

A code-review workflow for simplifying recently written or changed code while keeping its behavior the same. It looks for clearer structure, repeated logic, quality problems, and avoidable inefficiency.

In plain words
What is it for?
Use it after a feature, bug fix, or refactor to review the affected files, reuse existing helpers, remove unnecessary complexity, and follow the project's local conventions.
Why use it?
It helps make changed code easier to read and maintain without accidentally changing its outputs, errors, side effects, or public interfaces.

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/yz5e/agent-skills/code-simplifier
Any agent
npx skills add yz5e/agent-skills --skill code-simplifier
Clone the repo
git clone --depth 1 https://github.com/yz5e/agent-skills

Made for: Claude Code, Codex.

Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,395 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 $0.00096 $0.01395
Opus 5 $0.00048 $0.00698
Sonnet 5 $0.00019 $0.00279
Haiku 4.5 $0.00010 $0.00139

Measured 2d ago against content hash 5baf90362386, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

code-simplifier 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.

skills/code-simplifier/SKILL.md · 100 lines

How it starts

The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Code Simplifier

Simplify only the relevant changed code unless the user explicitly asks for a broader sweep. Preserve behavior, outputs, error semantics, side effects, and public interfaces.

Default to a single-agent simplification pass. Use spawn_agent only when the user explicitly asks for delegation, parallel subagents, or a multi-agent review and the touched scope is broad enough to benefit.

Workflow

  1. Identify the scope.
  • Prefer the files or hunks changed in the current task.
  • If the scope is unclear, inspect the named function, file, or recent diff.
  • Avoid unrelated cleanup outside the touched area.
  1. Read the project's local conventions.
  • Check AGENTS.md, nearby code, formatter and lint rules, and type patterns.
  • Match the repository's style instead of forcing a generic one.
  • Reuse existing helpers before introducing new abstractions or dependencies.
  1. Decide whether to delegate.
  • Keep the immediate blocking work local. Form a short plan before spawning anything.
  • Do not delegate small, tightly coupled, or urgent blocking work where your next step depends on the answer.
  • If the user explicitly asks for parallelism and the work is broad enough, use spawn_agent for bounded subtasks that can run in parallel with your local work.
  • Prefer narrow prompts and explicit file or symbol scope over copying the full thread context. Use fork_context only when the subagent truly needs the same conversation history.
  • Prefer explorer agents for read-heavy simplification analysis. Reserve worker agents for implementation only when the write scope can be split into disjoint files or modules.
  1. Review the code through three simplification lenses.
  • Reuse: prefer existing helpers, utilities, and local patterns before adding new abstractions; remove duplication when the shared shape is stable.
  • Quality: improve readability, naming, branching, cohesion, and type clarity; preserve logging, validation, and error semantics.
  • Efficiency: remove unnecessary work in the touched code such as redundant passes, allocations, awaits, or lookups when the improvement is obvious and behavior stays identical.
  • If the lenses conflict, prefer behavioral safety and readability over extra DRYing or micro-optimizations.

Read the full file on GitHub · 100 lines

Files

What ships with it

1 file 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 · 100 lines · 96 tokens per session scan A 5baf90362386

Subscribe to this mod's changes

code-simplifier is a skill published in the GitHub repository yz5e/agent-skills (16 stars, last pushed 4mo ago), licensed MIT. It adds 96 tokens to every session and 1,395 once invoked, about $0.0005 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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