skill-builder

skill-builder is a skill for Claude Code, Codex from AsiaOstrich/universal-dev-standards. It costs 164 tokens per session (2,049 once invoked), scanned A, original, no licence file.

A guide for turning a repeatable development process into a coding-agent skill. It covers when to use the skill, its core principles, decision-making, and where to place it.

In plain words
What is it for?
Use it when designing or documenting a new skill from an existing process.
Why use it?
It provides structure for packaging a useful workflow so an agent can follow it consistently.

Skill for Claude CodeCodex

Part of the universal-dev-standards plugin — 55 skills, 53 commands, 10 agents, 1 hook shipped together

Install

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.

agentmods
npx agentmods add skills/asiaostrich/universal-dev-standards/skill-builder
Any agent
npx skills add AsiaOstrich/universal-dev-standards --skill skill-builder
Clone the repo
git clone --depth 1 https://github.com/AsiaOstrich/universal-dev-standards

Made for: Claude Code, Codex.

Or install universal-dev-standards, the plugin that ships this one along with the rest of its 55 skills, 53 commands, 10 agents, 1 hook.

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 skill-builder

README.md
[![agentmods](https://agentmods.dev/badge/skills/asiaostrich/universal-dev-standards/skill-builder.svg)](https://agentmods.dev/skills/asiaostrich/universal-dev-standards/skill-builder)
Your own site
<a href="https://agentmods.dev/skills/asiaostrich/universal-dev-standards/skill-builder"><img src="https://agentmods.dev/badge/skills/asiaostrich/universal-dev-standards/skill-builder.svg" alt="Measured on agentmods" height="20"></a>
Per session 164 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,049 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00164 $0.02049
Opus 5 $0.00082 $0.01025
Sonnet 5 $0.00033 $0.00410
Haiku 4.5 $0.00016 $0.00205

Measured 4d ago against content hash 4a11b8d24d86, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

skill-builder 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 4d 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/skill-builder/SKILL.md · 170 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 4d ago First seen · 170 lines · 164 tokens per session scan A 4a11b8d24d86

Subscribe to this mod's changes

skill-builder is a skill published in the GitHub repository AsiaOstrich/universal-dev-standards (72 stars, last pushed 3d ago), with no licence file. It adds 164 tokens to every session and 2,049 once invoked, about $0.0008 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.