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 ag0os/rails-dev-plugin --skill ruby-refactoringgit clone --depth 1 https://github.com/ag0os/rails-dev-pluginWrote 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/ag0os/rails-dev-plugin/ruby-refactoring)<a href="https://agentmods.dev/skills/ag0os/rails-dev-plugin/ruby-refactoring"><img src="https://agentmods.dev/badge/skills/ag0os/rails-dev-plugin/ruby-refactoring/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/skills/ag0os/rails-dev-plugin/ruby-refactoring"><img src="https://agentmods.dev/badge/skills/ag0os/rails-dev-plugin/ruby-refactoring.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 | $0.00119 | $0.01313 |
| Opus 5.5 | $0.00048 | $0.00525 |
| Sonnet 5.5 | $0.00024 | $0.00263 |
| Haiku 4.5 | $0.00012 | $0.00131 |
Grade A, and why
ruby-refactoring 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.
How it starts
The opening of the file, as written. The whole thing — 120 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ruby Refactoring Expert
Systematic code improvement using the Ruby Science methodology and Fowler's established refactoring catalog.
Refactoring Methodology
Follow this 5-step process strictly. Do not skip steps.
Step 1: Identify Code Smells
Systematically scan using the smell-to-pattern matrix below. See code-smells.md for Rails-specific detection heuristics.
Step 2: Prioritize Issues
Rank every finding into one of three tiers:
| Priority | Criteria | Examples |
|---|---|---|
| High | Security risk, causes bugs across team, blocks feature work | N+1 in hot path, god class everyone edits, no test coverage on payment flow |
| Medium | Slows development, increases onboarding time, causes merge conflicts | Duplicated logic across 3+ files, 200-line method, shotgun surgery across layers |
| Low | Style inconsistency, minor readability, single-occurrence smell | One long parameter list, naming nitpick, unused private method |
Always attack high-impact, low-risk refactorings first. A refactoring is low-risk when existing tests cover the code path.
Step 3: Propose Solutions
Apply standard refactoring patterns from Fowler's catalog and Ruby Science. Use the decision matrix below to map smells to patterns. Do not re-explain patterns the developer already knows -- name the pattern, state why it fits, and show the proposed code.
Step 4: Consider Trade-offs
For every proposed refactoring, explicitly state:
- Will this introduce indirection that hurts readability?
- Is there measurable performance overhead?
- Does this require touching test files? How many?
- Could this be over-engineering for the current codebase size?
Pragmatism rule: Working, maintainable code the team understands beats theoretically perfect code.
Step 5: Verify Safety
Before and after every refactoring:
- Existing tests cover the code path (if not, write tests FIRST)
- Refactor in small, independently verifiable steps
- Run the test suite after each step
- Business logic is unchanged unless explicitly intended
What ships with it
2 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.
- 1mo ago First seen · 120 lines · 119 tokens per session scan A da07663d6a97
ruby-refactoring is a skill published in the GitHub repository ag0os/rails-dev-plugin (5 stars, last pushed 4mo ago), licensed MIT. It adds 119 tokens to every session and 1,313 once invoked, about $0.0005 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.
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