Borrowing it
Nothing to install: this file belongs to MokeyBytes/claude-baseline. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/MokeyBytes/claude-baseline/main/.claude/agents/performance-reviewer.mdgit clone --depth 1 https://github.com/MokeyBytes/claude-baselineWrote 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.
[](https://agentmods.dev/agents/mokeybytes/claude-baseline/performance-reviewer)<a href="https://agentmods.dev/agents/mokeybytes/claude-baseline/performance-reviewer"><img src="https://agentmods.dev/badge/agents/mokeybytes/claude-baseline/performance-reviewer/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.
<a href="https://agentmods.dev/agents/mokeybytes/claude-baseline/performance-reviewer"><img src="https://agentmods.dev/badge/agents/mokeybytes/claude-baseline/performance-reviewer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00040 | $0.00398 |
| Opus 5.5 | $0.00016 | $0.00159 |
| Sonnet 5.5 | $0.00008 | $0.00080 |
| Haiku 4.5 | $0.00004 | $0.00040 |
Grade A, and why
performance-reviewer 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 1mo 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.
What it actually says
Review the target code for performance issues. Report only — never modify files.
Database and query patterns
- N+1 queries: loops that trigger one query per iteration instead of a batched query
- Unbounded queries: endpoints or functions that fetch all rows without pagination or a limit
- Over-fetching:
SELECT *or fetching entire documents when only specific fields are needed - Missing indexes: filter or sort conditions on columns that are likely unindexed
Frontend (React and similar)
- Components that re-render on every parent render without memoization (
React.memo,useMemo) - Expensive computations inside render without
useMemo - Event handler functions recreated on every render without
useCallback - Large lists rendered without virtualization (
react-window,react-virtual)
General computation
- O(n²) or worse algorithms where a more efficient approach is achievable
- Repeated identical computations inside a loop that could be hoisted above it
- Synchronous blocking operations inside async or event-driven contexts
- Unnecessary deep copies of large objects or arrays
Resource usage
- Missing connection pooling for database or HTTP clients
- File handles or streams opened without guaranteed close
- Event listeners added without corresponding removal on cleanup or unmount
- Timers (
setInterval,setTimeout) not cleared on cleanup
Output format
For each issue: file path, line number, pattern name, estimated impact (High/Medium/Low), and recommended fix. Group by impact, highest first.
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.
- 1mo ago First seen · 43 lines · 40 tokens per session scan A 323f6355dc9a
performance-reviewer is an agent published in the GitHub repository MokeyBytes/claude-baseline (2 stars, last pushed 2mo ago), licensed MIT. It adds 40 tokens to every session and 398 once invoked, about $0.0002 per session on Opus 5.5. 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.
Other agents, from other repositories
code-reviewer
Review a completed diff for verified defects before a push or merge.
code-reviewer
Use this agent when a major project step has been completed and needs to be reviewed against the original plan and coding standards. Examples: Context: The user is creating a code-review agent that should be called after a logical chunk of code is written. user: "I've finished implementing the user authentication…
rdf-reviewer
Adversarial reviewer with two modes: challenge (pre-impl spec/plan review) and sentinel (post-impl 2-3 pass code review). Read-only — cannot modify source files. Dispatched by planner, dispatcher, or invoked via /r-review.
rdf-reviewer-challenge
Adversarial reviewer, challenge mode: pre-implementation spec/plan review (high effort). Read-only.
rdf-claims
Fresh-context claims checker. Verifies every factual claim in text about to be posted (PR bodies, commit messages, changelogs, release notes, issue or chat drafts) against primary evidence and returns per-claim verdicts with replacement text. Use for any claims check or fact check of written text.
cut
Over-engineering hunter. Extra files, wrappers, speculative types, unjustified deps. Use for /cut or "too much code".