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 moeru-ai/auv --skill m15-anti-patterngit clone --depth 1 https://github.com/moeru-ai/auvWrote 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/moeru-ai/auv/m15-anti-pattern)<a href="https://agentmods.dev/skills/moeru-ai/auv/m15-anti-pattern"><img src="https://agentmods.dev/badge/skills/moeru-ai/auv/m15-anti-pattern/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/moeru-ai/auv/m15-anti-pattern"><img src="https://agentmods.dev/badge/skills/moeru-ai/auv/m15-anti-pattern.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00101 | $0.01195 |
| Opus 5 | $0.00051 | $0.00598 |
| Sonnet 5 | $0.00020 | $0.00239 |
| Haiku 4.5 | $0.00010 | $0.00120 |
Grade A, and why
m15-anti-pattern 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 10d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- m15-anti-pattern — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Anti-Patterns
Layer 2: Design Choices
Core Question
Is this pattern hiding a design problem?
When reviewing code:
- Is this solving the symptom or the cause?
- Is there a more idiomatic approach?
- Does this fight or flow with Rust?
Anti-Pattern → Better Pattern
| Anti-Pattern | Why Bad | Better |
|---|---|---|
.clone() everywhere |
Hides ownership issues | Proper references or ownership |
.unwrap() in production |
Runtime panics | ?, expect, or handling |
Rc when single owner |
Unnecessary overhead | Simple ownership |
unsafe for convenience |
UB risk | Find safe pattern |
OOP via Deref |
Misleading API | Composition, traits |
| Giant match arms | Unmaintainable | Extract to methods |
String everywhere |
Allocation waste | &str, Cow<str> |
Ignoring #[must_use] |
Lost errors | Handle or let _ = |
Thinking Prompt
When seeing suspicious code:
-
Is this symptom or cause?
- Clone to avoid borrow? → Ownership design issue
- Unwrap "because it won't fail"? → Unhandled case
-
What would idiomatic code look like?
- References instead of clones
- Iterators instead of index loops
- Pattern matching instead of flags
-
Does this fight Rust?
- Fighting borrow checker → restructure
- Excessive unsafe → find safe pattern
Trace Up ↑
To design understanding:
"Why does my code have so many clones?"
↑ Ask: Is the ownership model correct?
↑ Check: m09-domain (data flow design)
↑ Check: m01-ownership (reference patterns)
| Anti-Pattern | Trace To | Question |
|---|---|---|
| Clone everywhere | m01-ownership | Who should own this data? |
| Unwrap everywhere | m06-error-handling | What's the error strategy? |
| Rc everywhere | m09-domain | Is ownership clear? |
| Fighting lifetimes | m09-domain | Should data structure change? |
Trace Down ↓
To implementation (Layer 1):
"Replace clone with proper ownership"
↓ m01-ownership: Reference patterns
↓ m02-resource: Smart pointer if needed
"Replace unwrap with proper handling"
↓ m06-error-handling: ? operator
↓ m06-error-handling: expect with message
What ships with it
1 file 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.
- 10d ago First seen · 161 lines · 101 tokens per session scan A bcbb49e47b76
m15-anti-pattern is a skill published in the GitHub repository moeru-ai/auv (27 stars, last pushed 2d ago), licensed Apache-2.0. It adds 101 tokens to every session and 1,195 once invoked, about $0.0005 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.
Other skills, from other repositories
architecture-audit
Systematic architecture audit and refactoring methodology for Rust + TypeScript codebases. Use when performing refactoring, cleanup, unification, code review, dead code removal, module reorganization, or tech debt elimination. Ensures no naming confusion, semantic overloading, hidden defaults, duplicate logic, or…
rust-review
A Rust code-review skill for services, checking for crashes, unsafe SQL construction, exposed credentials, ignored errors, and unfinished code.
rust-skills
Comprehensive Rust coding guidelines with 265 rules across 26 categories. Use when writing, reviewing, or refactoring Rust code. Covers ownership, error handling, async patterns, concurrency, unsafe code, API design, memory optimization, performance, numeric safety, conversions, serde, pattern matching, macros…
adversarial-rust
Use this skill when reviewing or refactoring existing Rust code that carries an alien mental model — OO/enterprise ceremony from Java/C#, garbage-collected object graphs, exception-style control flow, or imperative loops ported onto the borrow checker. It is the adversarial, architecture-level counterpart to…
writing-rust
Idiomatic Rust development. Use when writing Rust code, Cargo crates/workspaces, Rust tests, or rustfmt/clippy/cargo workflows. Emphasizes ownership, Result errors, small APIs, stdlib-first dependencies, fast cargo feedback, and behavior tests. NOT for Go, Python, TypeScript, shell scripts, or infra-only work.
architectural_review
Review Rust code for advanced architectural patterns — capability mixins, typed commands, concurrency model choice, smart pointer/interior mutability selection, error-handling architecture, and memory layout. Use when the user asks to review system architecture, suggest broad design improvements, or evaluate trait…