performance-review

performance-review is a skill for Claude Code, Codex from Arnosdeus/agent-toolkit. It costs 30 tokens per session (178 once invoked), scanned A, original, MIT.

A checklist for measuring and reviewing performance problems in websites, servers, and databases.

In plain words
What is it for?
It is for examining bundle size, rendering, network requests, caching, images, database queries, API delay, memory use, polling, and loading behavior.
Why use it?
It prevents speculative optimization by requiring evidence such as traces, metrics, profiling results, query plans, or repeatable measurements.

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/arnosdeus/agent-toolkit/performance-review
Any agent
npx skills add Arnosdeus/agent-toolkit --skill performance-review
Clone the repo
git clone --depth 1 https://github.com/Arnosdeus/agent-toolkit

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for performance-review

README.md
[![agentmods](https://agentmods.dev/badge/skills/arnosdeus/agent-toolkit/performance-review.svg)](https://agentmods.dev/skills/arnosdeus/agent-toolkit/performance-review)
Your own site
<a href="https://agentmods.dev/skills/arnosdeus/agent-toolkit/performance-review"><img src="https://agentmods.dev/badge/skills/arnosdeus/agent-toolkit/performance-review.svg" alt="Measured on agentmods" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 178 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 $0.00030 $0.00178
Opus 5 $0.00015 $0.00089
Sonnet 5 $0.00006 $0.00036
Haiku 4.5 $0.00003 $0.00018

Measured 3d ago against content hash 9ed05ab68c84, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

performance-review 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.

skills/performance-review/SKILL.md · 20 lines

What it actually says

Performance Review

Procedure and output

Establish a baseline or reproducible cost before recommending a change. Report BLOCKER, MAJOR, MINOR, or NOTE findings with metric, trace, query, or code evidence, plus the smallest justified remediation.

Look for measurable bundle and dependency cost, unnecessary re-renders, requests, missing caching, image inefficiency, inappropriate lazy loading or code splitting, slow queries/N+1 patterns, API latency, memory growth, polling, and loading behavior. Prefer traces, metrics, profiling, query plans, or reproducible measurements. Do not recommend speculative optimization; state the measurement needed when evidence is unavailable.

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 · 20 lines · 30 tokens per session scan A 9ed05ab68c84

Subscribe to this mod's changes

performance-review is a skill published in the GitHub repository Arnosdeus/agent-toolkit (2 stars, last pushed 10d ago), licensed MIT. It adds 30 tokens to every session and 178 once invoked, about $0.0002 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 2026-08-31.

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