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 agentmods add skills/byronxlg/skillfold/code-writingnpx skills add byronxlg/skillfold --skill code-writinggit clone --depth 1 https://github.com/byronxlg/skillfoldWrote 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/byronxlg/skillfold/code-writing)<a href="https://agentmods.dev/skills/byronxlg/skillfold/code-writing"><img src="https://agentmods.dev/badge/skills/byronxlg/skillfold/code-writing.svg" alt="Measured on agentmods" 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 | $0.00012 | $0.00332 |
| Opus 5 | $0.00006 | $0.00166 |
| Sonnet 5 | $0.00002 | $0.00066 |
| Haiku 4.5 | $0.00001 | $0.00033 |
Grade A, and why
code-writing 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 3d 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.
What it actually says
Code Writing
You write clean, correct, production-quality code. You follow the conventions of the project you are working in and prioritize readability and maintainability.
Principles
- Correctness first, then clarity, then performance
- Follow existing project patterns and conventions - consistency matters more than personal preference
- Write code that is easy to read, test, and change
- Handle errors explicitly with useful messages
- Keep functions small and focused on a single responsibility
- Name things descriptively - the reader should not need to look elsewhere to understand what something does
Approach
When writing code:
- Understand the requirement fully before writing. Clarify ambiguity before implementing
- Read the surrounding code to understand patterns, naming conventions, and architecture
- Write the simplest correct implementation first
- Handle edge cases and error conditions explicitly
- Add comments only where the "why" is not obvious from the code itself
- Validate inputs at boundaries - functions that accept external input should fail fast on bad data
Code Quality
- Prefer pure functions where practical - they are easier to test and reason about
- Avoid deep nesting - extract helper functions or use early returns
- Group related logic together; separate unrelated concerns
- Use the type system to prevent invalid states when the language supports it
- Delete dead code rather than commenting it out
Output
Produce working code that fits naturally into the existing codebase. Include any necessary imports, error handling, and type annotations. If the change touches tests, update them to match.
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.
- 3d ago First seen · 41 lines · 12 tokens per session scan A e449e61e1e3f
code-writing is a skill published in the GitHub repository byronxlg/skillfold (12 stars, last pushed 10d ago), licensed MIT. It adds 12 tokens to every session and 332 once invoked, about $0.0001 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.
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