writing-design-docs

writing-design-docs is a skill for Claude Code from riekelt/technical-writer. It costs 83 tokens per session (1,410 once invoked), scanned A, original, MIT.

A skill for writing design documents, such as proposals, technical specifications, RFCs, and migration plans. These documents explain a proposed change and invite discussion or approval.

In plain words
What is it for?
It helps draft and review documents that argue for a change, record its design, define its scope, or ask readers for input.
Why use it?
It provides a consistent structure for explaining the decision, benefits, costs, evidence, and open questions behind a change.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the technical-writer plugin — 11 skills, 2 commands, 2 agents 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/riekelt/technical-writer/writing-design-docs
Any agent
npx skills add riekelt/technical-writer --skill writing-design-docs
Clone the repo
git clone --depth 1 https://github.com/riekelt/technical-writer

Made for: Claude Code.

Or install technical-writer, the plugin that ships this one along with the rest of its 11 skills, 2 commands, 2 agents.

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 writing-design-docs

README.md
[![agentmods](https://agentmods.dev/badge/skills/riekelt/technical-writer/writing-design-docs.svg)](https://agentmods.dev/skills/riekelt/technical-writer/writing-design-docs)
Your own site
<a href="https://agentmods.dev/skills/riekelt/technical-writer/writing-design-docs"><img src="https://agentmods.dev/badge/skills/riekelt/technical-writer/writing-design-docs.svg" alt="Measured on agentmods" height="20"></a>
Per session 83 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,410 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 5.1 $0.00083 $0.01410
Opus 5 $0.00042 $0.00705
Sonnet 5 $0.00017 $0.00282
Haiku 4.5 $0.00008 $0.00141

Measured 6d ago against content hash ddcc3632f782, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

writing-design-docs 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 6d 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.

plugins/technical-writer/skills/writing-design-docs/SKILL.md · 108 lines

How it starts

The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Writing design docs

REQUIRED BACKGROUND: the technical-writing skill (read-first, hard rules, truth rules, style).

Overview

A design document is a proposal made discussable. Conclusion first, every non-trivial choice in a Why & What box, costs named next to benefits, and fact separated from proposal.

When to invoke, and not

Invoke for anything that argues for a change or records a design: proposals, RFCs, design docs, specs, migration plans, "should we" documents. Do NOT invoke for recording an already-taken decision (recording-decisions), for procedures (writing-runbooks), or for status reports.

Steering under pressure: a proposal persuades with its numbers and its named costs, and the register rules hold whatever the deadline (the technical-writing rule; "punchy" is not an override). When supplied facts arrive without sources, mark them **[source wanted: ...]** and keep writing (see references/truth.md in the technical-writing skill); never invent a citation and never silently drop the fact.

Skeleton

# Title: what the document does

**Subtitle pinning the scope in one sentence**

|                |                                            |
| -------------- | ------------------------------------------ |
| **Status**     | Draft / Request for comments               |
| **Owner**      | [team or role]                             |
| **Scope**      | [explicit, including what falls outside]   |
| **Related**    | [links to sibling documents]               |
| **Audience**   | [who must read this]                       |

---

## 1. Summary
[The answer immediately. Not the occasion, not the method: the conclusion.]

## 2. [Context / what was analyzed]
## 3. [The analysis, split per question]
## n. Open questions
## n+1. Benefits and costs
[Both. A proposal that lists only benefits reads as a sales pitch.]
## n+2. Residual risks and what not to do
[Only when the design hands work to other teams.]

---

*Closing line: which parts are fact and which are proposal, and where input is wanted.*

Read the full file on GitHub · 108 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. 6d ago First seen · 108 lines · 83 tokens per session scan A ddcc3632f782

Subscribe to this mod's changes

writing-design-docs is a skill published in the GitHub repository riekelt/technical-writer (15 stars, last pushed 7d ago), licensed MIT. It adds 83 tokens to every session and 1,410 once invoked, about $0.0004 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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