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.
npx agentmods add skills/el-feo/ai-context/rubycriticnpx skills add el-feo/ai-context --skill rubycriticgit clone --depth 1 https://github.com/el-feo/ai-contextWhat 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 | $0.00063 | $0.00459 |
| Opus 5 | $0.00032 | $0.00230 |
| Sonnet 5 | $0.00013 | $0.00092 |
| Haiku 4.5 | $0.00006 | $0.00046 |
Grade A, and why
rubycritic 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.
What it actually says
RubyCritic Code Quality Analysis
Quick Start
Run quality check on Ruby files:
scripts/check_quality.sh [path/to/ruby/files]
Analyzes the current directory if no path provided. Auto-installs RubyCritic if missing.
Check recently modified files:
scripts/check_quality.sh $(git diff --name-only | grep '\.rb$')
Workflow
Run RubyCritic automatically:
- After creating new Ruby files or classes
- After implementing complex methods (>10 lines)
- After refactoring existing code
- Before marking tasks as complete
Skip for: simple variable renames, comment changes, minor formatting.
Interpreting Results
- Score 90+: Good. Score 95+ is excellent.
- Score 80-89: Consider refactoring.
- Below 80: Prioritize improvements.
- File ratings: A/B acceptable, C needs attention, D/F requires refactoring.
RubyCritic combines three analyzers:
- Reek (code smells) - design and readability issues
- Flog (complexity) - overly complex methods
- Flay (duplication) - repeated code patterns
Responding to Issues
Fix in priority order: high complexity > duplication > code smells > style.
Fix one issue at a time, re-run after each fix, verify score improves.
References
- references/code_smells.md - Common smells with before/after examples
- references/configuration.md -
.rubycritic.ymloptions, CI mode, score calculation - references/git-hooks.md - Pre-commit hooks and CI/CD integration
- references/error-handling.md - Troubleshooting installation and analysis errors
What ships with it
5 files 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.
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.
- 2d ago First seen · 58 lines · 63 tokens per session scan A e92556e2aa2f
rubycritic is a skill published in the GitHub repository el-feo/ai-context (12 stars, last pushed 1mo ago), licensed MIT. It adds 63 tokens to every session and 459 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.
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