ownyourcode: Skill for Claude Code

.claude/skills/fundamentals/engineering/SKILL.md

engineering-fundamentals is a skill for Claude Code from DanielPodolsky/ownyourcode. It costs 47 tokens per session (1,373 once invoked), scanned A, original, MIT.

A checklist for reviewing code structure and readability, including names, function design, duplication, and organization.

In plain words
What is it for?
Code reviews, refactoring, naming decisions, checking function size and responsibilities, and evaluating whether abstractions are justified.
Why use it?
Code that works can still be difficult to understand, change, or maintain. The checklist helps identify common design and clarity problems.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

This is DanielPodolsky/ownyourcode's own configuration. It tells Claude Code how to work on ownyourcode itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ownyourcode configures →

Reuse

Borrowing it

Nothing to install: this file belongs to DanielPodolsky/ownyourcode. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/DanielPodolsky/ownyourcode/main/.claude/skills/fundamentals/engineering/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/DanielPodolsky/ownyourcode

Made for: Claude Code.

Wrote 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.

agentmods badge for engineering-fundamentals

README.md
[![agentmods](https://agentmods.dev/badge/skills/danielpodolsky/ownyourcode/engineering/github.svg)](https://agentmods.dev/skills/danielpodolsky/ownyourcode/engineering)
Your own site
<a href="https://agentmods.dev/skills/danielpodolsky/ownyourcode/engineering"><img src="https://agentmods.dev/badge/skills/danielpodolsky/ownyourcode/engineering/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.

agentmods 80×15 button for engineering-fundamentals

Your own site · 80×15
<a href="https://agentmods.dev/skills/danielpodolsky/ownyourcode/engineering"><img src="https://agentmods.dev/badge/skills/danielpodolsky/ownyourcode/engineering.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,373 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00047 $0.01373
Opus 5.5 $0.00019 $0.00549
Sonnet 5.5 $0.00009 $0.00275
Haiku 4.5 $0.00005 $0.00137

Measured 1mo ago against content hash 6d2e3a8861b8, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

engineering-fundamentals 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.

.claude/skills/fundamentals/engineering/SKILL.md · 183 lines

How it starts

The opening of the file, as written. The whole thing — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Engineering Fundamentals Review

"Code is read more than it is written. Write for the reader, not the machine."

When to Apply

Activate this skill when reviewing:

  • Any code changes
  • Function and variable naming
  • Code organization and structure
  • General refactoring decisions

Review Checklist

Naming

  • Descriptive: Can you understand the variable without context?
  • No abbreviations: Are names spelled out? (user not usr)
  • No generic names: No data, temp, info, stuff?
  • Boolean prefix: Do booleans start with is, has, can, should?
  • Function verbs: Do functions start with action verbs?

Function Design

  • Single responsibility: Does each function do ONE thing?
  • Size limit: Are functions under 20-30 lines?
  • Parameter count: Are there fewer than 4 parameters?
  • No side effects: Are pure functions actually pure?
  • Early returns: Are guard clauses used instead of deep nesting?

Code Organization

  • DRY: Is duplicated code extracted into functions?
  • But not too DRY: Are abstractions justified (rule of three)?
  • Cohesion: Are related things grouped together?
  • Separation: Are unrelated things separated?

Comments & Documentation

  • Why, not what: Do comments explain reasoning, not obvious code?
  • No commented-out code: Is dead code deleted, not commented?
  • JSDoc on public APIs: Are exported functions documented?

Common Mistakes (Anti-Patterns)

1. Magic Numbers

❌ if (status === 2) { ... }
   setTimeout(callback, 86400000);

✅ const STATUS = { ACTIVE: 2, INACTIVE: 1 };
   if (status === STATUS.ACTIVE) { ... }

   const ONE_DAY_MS = 24 * 60 * 60 * 1000;
   setTimeout(callback, ONE_DAY_MS);

2. Unclear Naming

❌ const d = new Date();
   const temp = getUser();
   const flag = true;

✅ const createdAt = new Date();
   const currentUser = getUser();
   const isAuthenticated = true;

Read the full file on GitHub · 183 lines

Changes

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.

  1. 1mo ago First seen · 183 lines · 47 tokens per session scan A 6d2e3a8861b8

Subscribe to this mod's changes

engineering-fundamentals is a skill published in the GitHub repository DanielPodolsky/ownyourcode (292 stars, last pushed 4mo ago), licensed MIT. It adds 47 tokens to every session and 1,373 once invoked, about $0.0002 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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