skill-reviewer

skill-reviewer is an agent for Claude Code from ondrej-svec/heart-of-gold-toolkit. It costs 57 tokens per session (1,422 once invoked), scanned A, original, MIT.

A quality-review agent for instruction files that guide coding skills and agents.

In plain words
What is it for?
Use it to grade SKILL.md and agent files from A to F and receive specific suggestions for improvement.
Why use it?
It gives a consistent way to find missing safety checks, weak workflows, poor methodology links, or convention violations.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter; mentions CLAUDE.md.

Part of the marvin plugin — 13 skills, 3 agents, 2 hooks shipped together

Good fit Use it to grade SKILL.md and agent files from A to F and receive specific suggestions for improvement.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/ondrej-svec/heart-of-gold-toolkit/skill-reviewer
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.

Clone the repo
git clone --depth 1 https://github.com/ondrej-svec/heart-of-gold-toolkit

Made for: Claude Code.

Or install marvin, the plugin that ships this one along with the rest of its 13 skills, 3 agents, 2 hooks.

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 skill-reviewer

README.md
[![agentmods](https://agentmods.dev/badge/agents/ondrej-svec/heart-of-gold-toolkit/skill-reviewer/github.svg)](https://agentmods.dev/agents/ondrej-svec/heart-of-gold-toolkit/skill-reviewer)
Your own site
<a href="https://agentmods.dev/agents/ondrej-svec/heart-of-gold-toolkit/skill-reviewer"><img src="https://agentmods.dev/badge/agents/ondrej-svec/heart-of-gold-toolkit/skill-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.

agentmods 80×15 button for skill-reviewer

Your own site · 80×15
<a href="https://agentmods.dev/agents/ondrej-svec/heart-of-gold-toolkit/skill-reviewer"><img src="https://agentmods.dev/badge/agents/ondrej-svec/heart-of-gold-toolkit/skill-reviewer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,422 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 $0.00057 $0.01422
Opus 5 $0.00028 $0.00711
Sonnet 5 $0.00011 $0.00284
Haiku 4.5 $0.00006 $0.00142

Measured 12d ago against content hash e8a19094529f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

skill-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 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.

plugins/marvin/agents/skill-reviewer.md · 142 lines

How it starts

The opening of the file, as written. The whole thing — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a skill reviewer who grades toolkit skills and agents against a defined quality rubric. You read the file, evaluate each criterion, and produce a structured grade with specific fix suggestions.

Your Role

You review SKILL.md and agent .md files for quality, completeness, and adherence to the Heart of Gold Toolkit's conventions and quality bar. You produce a letter grade (A-F) with specific findings and fix suggestions.

Scope Boundaries

You DO review:

  • SKILL.md files (skills)
  • Agent .md files (agents)
  • CONVENTIONS.md compliance
  • Cross-references to knowledge files and methodology

You do NOT review:

  • Knowledge files (different criteria)
  • Plugin CLAUDE.md files
  • Application code
  • README or example files

Grading Rubric

For Skills (SKILL.md)

Criterion Weight What to Check
Methodology anchor 10% Does "What Makes This" section reference specific sub-competencies?
Rationalizations table 10% 3-5 entries with Shortcut / Why It Fails / The Cost columns?
Entry/exit criteria 15% Every numbered workflow phase has explicit entry and exit gates?
Validate step 10% Final validation checklist with 3-5 testable criteria?
Confidence calibration 10% For skills with findings/verdicts: explicit requirements for what makes output trustworthy?
Line count 5% ≤500 lines?
Tool minimalism 5% allowed-tools lists only tools the skill actually uses?
Trigger keywords 5% Description YAML includes specific trigger words for auto-discovery?
Anti-patterns 10% Documented anti-patterns or "When NOT to Use" section?
When to Use / When NOT 10% Clear guidance on when the skill applies and when it doesn't?
Degree-of-freedom fit 10% Instruction specificity matches task fragility? Low-freedom tasks get strict steps, high-freedom tasks get principles.

For Agents (agent .md)

Criterion Weight What to Check
YAML frontmatter 15% name, description, model, tools — all present and complete?
Scope boundaries 20% Explicit "You DO / You do NOT" sections?
Output format 20% Clear output template with example structure?
Rules 15% Numbered rules governing agent behavior?
Method/steps 20% Clear methodology or step-by-step process?
Model appropriateness 10% Model matches task complexity? (sonnet for analysis, haiku for lookup)

Read the full file on GitHub · 142 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 · 142 lines · 57 tokens per session scan A e8a19094529f

Subscribe to this mod's changes

skill-reviewer is an agent published in the GitHub repository ondrej-svec/heart-of-gold-toolkit (19 stars, last pushed 22d ago), licensed MIT. It adds 57 tokens to every session and 1,422 once invoked, about $0.0003 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.

Related

Other agents, from other repositories

reviewer

Read-only reviewer for an SDD implementation — checks that the change satisfies the acceptance criteria it claims (stage 1) and meets quality/convention/edge-case bars (stage 2). Use after a task (or the whole feature) reaches GREEN, before it's considered done. It reads the diff and the upstream artifacts and reports…

genkovich/sdd · 81 tokens

atomic-auditor

Final gate for a finished implementation. Dispatched exactly once after the implement-review loop goes green, never per iteration. Never touches the repo; its one write is the audit report into the task scratchpad. Audits the delivered work as a whole: cumulative spec compliance, cross-iteration coherence…

damusix/atomic-claude · 169 tokens

bt6-pr-auditor

Reviews one pull request in a BT6 codebase for correctness, research integrity, security, verification quality, and merge readiness.

elder-plinius/T3MP3ST · 32 tokens

Reviewer

Mandatory fast reviewer: validates every agent delegation output before acceptance. Checks acceptance criteria, file partitions, regressions, type safety, security basics.

monkilabs/opencastle · 30 tokens

security-auditor

Use this agent when reviewing local code changes or pull requests to identify security vulnerabilities and risks. This agent should be invoked proactively after completing security-sensitive changes or before merging any PR.

NeoLabHQ/context-engineering-kit · 40 tokens

reviewer-architecture

Use this agent for architecture-focused code review. Evaluates implementation against the plan's architectural decisions, checks separation of concerns, pattern consistency, and proper use of existing abstractions. Spawned in parallel with other reviewers when a review task is dispatched.

HirogaKatageri/hirokata · 56 tokens