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 skills add el-feo/ai-context --skill rubocopgit clone --depth 1 https://github.com/el-feo/ai-contextWrote 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/skills/el-feo/ai-context/rubocop)<a href="https://agentmods.dev/skills/el-feo/ai-context/rubocop"><img src="https://agentmods.dev/badge/skills/el-feo/ai-context/rubocop.svg" alt="Measured on agentmods" 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 | $0.00037 | $0.01569 |
| Opus 5 | $0.00018 | $0.00785 |
| Sonnet 5 | $0.00007 | $0.00314 |
| Haiku 4.5 | $0.00004 | $0.00157 |
Grade A, and why
rubocop 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 7d 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.
How it starts
The opening of the file, as written. The whole thing — 272 lines — stays where its author put it; the contents beside it link to each section on GitHub.
RuboCop Code Analysis & Formatting
RuboCop is Ruby's premier static code analyzer (linter) and formatter, based on the community-driven Ruby Style Guide. This skill enables comprehensive code analysis, automatic formatting, and enforcement of coding standards across Ruby projects including Rails applications.
When to Use This Skill
Claude automatically uses this skill when users:
- Ask to "check", "lint", "analyze", or "review" Ruby code
- Request code formatting or style improvements
- Want to enforce coding standards or style guidelines
- Need to detect potential bugs or code smells
- Ask about RuboCop configuration or setup
- Request Rails, RSpec, or performance-specific analysis
- Want to run autocorrections on Ruby code
Core Capabilities
Code Analysis & Linting
- Detects style violations, bugs, and code smells across all cop departments
- Supports Rails, RSpec, Performance, and custom cop extensions
- Provides detailed offense reports with line numbers and descriptions
Automatic Code Correction
- Safe autocorrection (
-a) for guaranteed-safe fixes - Unsafe autocorrection (
-A) for broader but riskier corrections - Layout-only fixes (
-x) for formatting without logic changes
Configuration & Customization
- Flexible
.rubocop.ymlconfiguration - Per-project and per-directory configuration inheritance
- Selective cop enabling/disabling and severity adjustment
- Custom cop development support
Extension Integration
- rubocop-rails: Rails best practices and conventions
- rubocop-rspec: RSpec-specific analysis
- rubocop-performance: Performance optimization checks
Quick Analysis Workflow
Run Basic Analysis
# Analyze current directory
rubocop
# Analyze specific files/directories
rubocop app spec lib/important_file.rb
# Show only correctable offenses
rubocop --display-only-correctable
Apply Corrections
# Safe autocorrection only (recommended)
rubocop -a
# All corrections including unsafe
rubocop -A
# Layout/formatting corrections only
rubocop -x
# Autocorrect specific cops
rubocop -a --only Style/StringLiterals,Layout/TrailingWhitespace
What ships with it
6 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.
- 7d ago First seen · 272 lines · 37 tokens per session scan A e2e6dcd1ad4e
rubocop is a skill published in the GitHub repository el-feo/ai-context (12 stars, last pushed 1mo ago), licensed MIT. It adds 37 tokens to every session and 1,569 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 2026-08-30.
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