critic-perf-budget

critic-perf-budget is a skill for Claude Code from iampawan/Manifest. It costs 34 tokens per session (760 once invoked), scanned A, original, MIT.

A review tool that checks whether each documented behavior has a measurable performance limit, such as page-start time or network response time.

In plain words
What is it for?
Use it to assess whether performance targets exist, are numeric, and cover the important work a feature performs.
Why use it?
It prevents features from passing review without stating how fast they need to be.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the manifest plugin — 28 skills, 15 commands shipped together

Good fit Use it to assess whether performance targets exist, are numeric, and cover the important work a feature performs.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/iampawan/manifest/critic-perf-budget
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.

Any agent
npx skills add iampawan/Manifest --skill critic-perf-budget
Clone the repo
git clone --depth 1 https://github.com/iampawan/Manifest

Made for: Claude Code.

Or install manifest, the plugin that ships this one along with the rest of its 28 skills, 15 commands.

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 critic-perf-budget

README.md
[![agentmods](https://agentmods.dev/badge/skills/iampawan/manifest/critic-perf-budget/github.svg)](https://agentmods.dev/skills/iampawan/manifest/critic-perf-budget)
Your own site
<a href="https://agentmods.dev/skills/iampawan/manifest/critic-perf-budget"><img src="https://agentmods.dev/badge/skills/iampawan/manifest/critic-perf-budget/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for critic-perf-budget

Your own site · 80×15
<a href="https://agentmods.dev/skills/iampawan/manifest/critic-perf-budget"><img src="https://agentmods.dev/badge/skills/iampawan/manifest/critic-perf-budget.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 34 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 760 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00034 $0.00760
Opus 5 $0.00017 $0.00380
Sonnet 5 $0.00007 $0.00152
Haiku 4.5 $0.00003 $0.00076

Measured 12d ago against content hash fcfaf4ec0a94, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

critic-perf-budget 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 12d 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/critic-perf-budget/SKILL.md · 81 lines

How it starts

The opening of the file, as written. The whole thing — 81 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Perf-budget critic

Protocol: Follow reference/CRITIC-RULES.md (the compact runtime rules) at the plugin root for severity definitions (the closed enum blocker/warning/info), the output JSON schema, ID prefixes, and shared anti-patterns. This skill defines only WHAT to look for. Do not invent severities like "high"/"medium" — the validator rejects them. Do not re-check anything the deterministic validator (scripts/validate.mjs) already covers; add the judgment layer on top.

A feature without a perf budget can't fail performance review — by definition. This critic prevents that loophole.

Gating is contextual + configurable (handled by the validator, not you). Field presence is governed by conventions.perfBudget / the contract's perfBudgetPolicy: required (blocker), warn (warning — the default), or off. When checked, one relevant numeric field is enough (ttiMs for UI, p95LatencyMs for a network call). Don't emit a presence finding the validator already handles — your job is the judgment layer: are the declared budgets realistic for the platform, and do they cover the behavior's real hot path?

What to check

1. Every behavior has perfBudget

Each ### B<N> must declare:

- perfBudget:
    ttiMs: <integer>            # Time to Interactive for the screen
    p95LatencyMs: <integer>     # backend response time
    errorRatePct: <number>      # max acceptable error rate %

Missing any field → blocker.

2. Budgets are concrete numbers, not "fast"

If any field is TBD or a string, emit a blocker with a suggested default based on the behavior type:

  • Page load behaviors: tti ≤ 2500ms, error ≤ 1%
  • API-triggered behaviors: p95 latency ≤ 800ms, error ≤ 0.5%
  • Background syncs: p95 latency ≤ 5000ms, error ≤ 2%

3. Budgets are realistic for the platform

If the contract's platforms includes mobile and the perf budget assumes desktop-class network (tti ≤ 500ms), flag as warning — mobile p95 network is generally 1500ms+ for cold loads.

Read the full file on GitHub · 81 lines

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. 12d ago First seen · 81 lines · 34 tokens per session scan A fcfaf4ec0a94

Subscribe to this mod's changes

critic-perf-budget is a skill published in the GitHub repository iampawan/Manifest (5 stars, last pushed 9d ago), licensed MIT. It adds 34 tokens to every session and 760 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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