write-gdd

write-gdd is a skill for Claude Code, Codex from jackli12/codex-game-studio. It costs 51 tokens per session (204 once invoked), scanned A, original, MIT.

A game design document writer. A game design document is a structured description of a game’s concept, gameplay systems, and production needs.

In plain words
What is it for?
It is for drafting or refining a game design document, identifying open risks, and handing implementation planning to the next role.
Why use it?
It turns scattered ideas and notes into an organized document and shows which design decisions are still missing.

Skill for Claude CodeCodex

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/jackli12/codex-game-studio/write-gdd
Any agent
npx skills add jackli12/codex-game-studio --skill write-gdd
Clone the repo
git clone --depth 1 https://github.com/jackli12/codex-game-studio

Made for: Claude Code, Codex.

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 write-gdd

README.md
[![agentmods](https://agentmods.dev/badge/skills/jackli12/codex-game-studio/write-gdd.svg)](https://agentmods.dev/skills/jackli12/codex-game-studio/write-gdd)
Your own site
<a href="https://agentmods.dev/skills/jackli12/codex-game-studio/write-gdd"><img src="https://agentmods.dev/badge/skills/jackli12/codex-game-studio/write-gdd.svg" alt="Measured on agentmods" height="20"></a>
Per session 51 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 204 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00051 $0.00204
Opus 5 $0.00026 $0.00102
Sonnet 5 $0.00010 $0.00041
Haiku 4.5 $0.00005 $0.00020

Measured 3d ago against content hash 7ecf349f46ac, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

write-gdd 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.

write-gdd/SKILL.md · 34 lines

What it actually says

Write GDD

目标

把概念和玩法方向整理成结构化的游戏设计文档。

何时使用

  • 项目需要正式的设计文档
  • 现有设计笔记比较零散

工作流

  1. 收集概念与系统输入
  2. 按结构组织文档章节
  3. 标出缺失的设计决策
  4. 把实现计划交给 plan-production

输出要求

  • 结构化 GDD 草稿
  • 缺失决策
  • 开放风险
  • 下一步交接对象

参考资料

  • ../shared/references/gdd-template.md
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. 3d ago First seen · 34 lines · 51 tokens per session scan A 7ecf349f46ac

Subscribe to this mod's changes

write-gdd is a skill published in the GitHub repository jackli12/codex-game-studio (12 stars, last pushed 3mo ago), licensed MIT. It adds 51 tokens to every session and 204 once invoked, about $0.0003 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.