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 heyAyushh/stacc --skill anti-patternsgit clone --depth 1 https://github.com/heyAyushh/staccWrote 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/heyayushh/stacc/anti-patterns)<a href="https://agentmods.dev/skills/heyayushh/stacc/anti-patterns"><img src="https://agentmods.dev/badge/skills/heyayushh/stacc/anti-patterns/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/heyayushh/stacc/anti-patterns"><img src="https://agentmods.dev/badge/skills/heyayushh/stacc/anti-patterns.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 | $0.00044 | $0.00753 |
| Opus 5 | $0.00022 | $0.00377 |
| Sonnet 5 | $0.00009 | $0.00151 |
| Haiku 4.5 | $0.00004 | $0.00075 |
Grade A, and why
rust-anti-patterns 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 9d 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 — 96 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?
Top 5 Beginner Mistakes
| Rank | Mistake | Fix |
|---|---|---|
| 1 | Clone to escape borrow checker | Use references |
| 2 | Unwrap in production | Propagate with ? |
| 3 | String for everything | Use &str |
| 4 | Index loops | Use iterators |
| 5 | Fighting lifetimes | Restructure to own data |
Anti-Pattern Reference
| Anti-Pattern | Why Bad | Better |
|---|---|---|
.clone() everywhere |
Hides ownership issues | Proper references or ownership |
.unwrap() in production |
Runtime panics | ?, expect, or matching |
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 _ = |
Code Smell → Refactoring
| Smell | Indicates | Refactoring |
|---|---|---|
Many .clone() |
Ownership unclear | Clarify data flow |
Many .unwrap() |
Error handling missing | Add proper handling |
Many pub fields |
Encapsulation broken | Private + accessors |
| Deep nesting | Complex logic | Extract methods |
| Long functions | Multiple responsibilities | Split |
| Giant enums | Missing abstraction | Trait + types |
Quick Review Checklist
- No
.clone()without justification - No
.unwrap()in library code - No
pubfields with invariants - No index loops when iterator works
- No
Stringwhere&strsuffices - No ignored
#[must_use]warnings - No
unsafewithout// SAFETY:comment - No giant functions (>50 lines)
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.
- 9d ago First seen · 96 lines · 44 tokens per session scan A 6077ff0a7f91
rust-anti-patterns is a skill published in the GitHub repository heyAyushh/stacc (3 stars, last pushed 2mo ago), licensed MIT. It adds 44 tokens to every session and 753 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 2026-09-03.
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…
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.
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…
m15-anti-pattern
Use when reviewing code for anti-patterns. Keywords: anti-pattern, common mistake, pitfall, code smell, bad practice, code review, is this an anti-pattern, better way to do this, common mistake to avoid, why is this bad, idiomatic way, beginner mistake, fighting borrow checker, clone everywhere, unwrap in production…