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 smallnest/pigo --skill refactorgit clone --depth 1 https://github.com/smallnest/pigoWrote 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/smallnest/pigo/refactor)<a href="https://agentmods.dev/skills/smallnest/pigo/refactor"><img src="https://agentmods.dev/badge/skills/smallnest/pigo/refactor/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/smallnest/pigo/refactor"><img src="https://agentmods.dev/badge/skills/smallnest/pigo/refactor.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Tool Misuse · line 665 Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
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 | $0.00071 | $0.05400 |
| Opus 5.5 | $0.00028 | $0.02160 |
| Sonnet 5.5 | $0.00014 | $0.01080 |
| Haiku 4.5 | $0.00007 | $0.00540 |
Grade A, and why
refactor 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 — 674 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Refactor — Expert Code Restructuring
Surgical code refactoring based on Martin Fowler's (2nd Edition) catalog. Improve structure, readability, and maintainability without changing external behavior. Gradual evolution, not revolution.
When to Use
This skill activates when:
- Code is hard to understand or maintain
- Functions/classes have grown too large
- Code smells are detected
- Adding features is difficult due to poor structure
- User explicitly requests refactoring, cleanup, or improvement
- User says: refactor, 重构, clean up, improve code, code smell, extract method, rename, simplify
The Golden Rules
These five rules are non-negotiable. Violating any of them turns refactoring into reckless editing.
1. Behavior is Preserved
Only how the code works changes, never what it does. If tests existed before, they must pass after. If the refactoring introduces a behavioral change, it's not refactoring — it's rewriting.
2. Small Steps
Each change should be the smallest possible transformation that compiles and passes tests. If a step breaks, you know exactly which change caused it. Refactoring is a series of tiny, safe transformations, not one big rewrite.
3. Version Control is Your Friend
Commit before starting. Commit after each successful step. This gives you infinite undo. Branch from a clean state so you can abandon the refactoring without consequences.
4. Tests are Essential
"Without tests, you're not refactoring — you're just editing." If tests don't exist for the target code, write characterization tests first. These tests capture the current behavior so you can detect regressions.
5. One Thing at a Time
Never mix refactoring with feature changes. Never refactor two unrelated things simultaneously. Each commit should contain exactly one refactoring operation.
When NOT to Refactor
| Scenario | Action |
|---|---|
| Code works and won't change again | Leave it alone |
| Critical production path with no tests | Write characterization tests first |
| Under tight deadline pressure | Document the smell, refactor later |
| No clear purpose or benefit | Don't refactor for refactoring's sake |
| Code is fundamentally wrong | This is a rewrite, not a refactoring |
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 · 674 lines · 71 tokens per session scan A 1c6dbf79647c
refactor is a skill published in the GitHub repository smallnest/pigo (483 stars, last pushed 1mo ago), licensed MIT. It adds 71 tokens to every session and 5,400 once invoked, about $0.0003 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 2026-08-30.
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