shipyard-writing-plans

shipyard-writing-plans is a skill for Claude Code from lgbarn/shipyard. It costs 96 tokens per session (2,424 once invoked), scanned A, original, MIT.

A method for turning a specification or design into small, executable implementation tasks before code is written.

In plain words
What is it for?
It helps plan features, break down projects, identify files and tests to change, and prepare tasks for coding agents.
Why use it?
It gives developers a shared, detailed path through multi-step work and reduces vague or missed requirements.

Skill for Claude Code

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

Part of the shipyard plugin — 25 skills, 25 commands, 20 agents, 6 hooks shipped together

Good fit It helps plan features, break down projects, identify files and tests to change, and prepare tasks for coding agents.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/lgbarn/shipyard/shipyard-writing-plans
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.

Any agent
npx skills add lgbarn/shipyard --skill shipyard-writing-plans
Clone the repo
git clone --depth 1 https://github.com/lgbarn/shipyard

Made for: Claude Code.

Or install shipyard, the plugin that ships this one along with the rest of its 25 skills, 25 commands, 20 agents, 6 hooks.

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 shipyard-writing-plans

README.md
[![agentmods](https://agentmods.dev/badge/skills/lgbarn/shipyard/shipyard-writing-plans/github.svg)](https://agentmods.dev/skills/lgbarn/shipyard/shipyard-writing-plans)
Your own site
<a href="https://agentmods.dev/skills/lgbarn/shipyard/shipyard-writing-plans"><img src="https://agentmods.dev/badge/skills/lgbarn/shipyard/shipyard-writing-plans/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 shipyard-writing-plans

Your own site · 80×15
<a href="https://agentmods.dev/skills/lgbarn/shipyard/shipyard-writing-plans"><img src="https://agentmods.dev/badge/skills/lgbarn/shipyard/shipyard-writing-plans.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,424 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 warn 7 Sept 2026
SkillSpector: 2 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Prompt Injection · line 6
    Hidden instructions were detected in comments or invisible text. These could contain malicious directives. Manual review is recommended.
    Fix: Audit all comments and invisible characters. Remove any instructions that direct the agent to perform unauthorized actions. Use plain, reviewable content.
  • medium Excessive Agency · line 236
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 $0.00096 $0.02424
Opus 5 $0.00048 $0.01212
Sonnet 5 $0.00019 $0.00485
Haiku 4.5 $0.00010 $0.00242

Measured 7d ago against content hash d61f6c228752, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

shipyard-writing-plans 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 7d 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/shipyard/skills/shipyard-writing-plans/SKILL.md · 291 lines

How it starts

The opening of the file, as written. The whole thing — 291 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Writing Plans

When This Skill Activates

  • You have a spec, requirements, or design for a multi-step implementation task
  • You need to break work into bite-sized, executable tasks before touching code
  • You are preparing work for builder agents or a parallel execution session

Announce at start: "I'm using the writing-plans skill to create the implementation plan."

Context: This should be run in a dedicated worktree (created by brainstorming skill).

Save plans to: docs/plans/YYYY-MM-DD-<feature-name>.md

Natural Language Triggers

  • "write a plan", "create a plan", "plan this feature", "break this down into tasks"

Overview

Write comprehensive implementation plans assuming the engineer has zero context for our codebase and questionable taste. Document everything they need to know: which files to touch for each task, code, testing, docs they might need to check, how to test it. Give them the whole plan as bite-sized tasks. DRY. YAGNI. TDD. Frequent commits.

Assume they are a skilled developer, but know almost nothing about our toolset or problem domain. Assume they don't know good test design very well.

Shipyard Plan Format

Shipyard plans use XML-structured tasks with verification criteria. Each task includes:

<task id="1" name="Component Name">
  <description>What this task accomplishes</description>
  <files>
    <create>exact/path/to/file.py</create>
    <modify>exact/path/to/existing.py:123-145</modify>
    <test>tests/exact/path/to/test.py</test>
  </files>
  <steps>
    <step>Write the failing test</step>
    <step>Run test to verify it fails</step>
    <step>Write minimal implementation</step>
    <step>Run test to verify it passes</step>
    <step>Commit</step>
  </steps>
  <verification>
    <command>pytest tests/path/test.py::test_name -v</command>
    <expected>PASS</expected>
  </verification>
</task>

This structured format enables /shipyard:build to parse and execute tasks systematically, and /shipyard:status to track progress.

Read the full file on GitHub · 291 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. 7d ago First seen · 291 lines · 96 tokens per session scan A d61f6c228752

Subscribe to this mod's changes

shipyard-writing-plans is a skill published in the GitHub repository lgbarn/shipyard (65 stars, last pushed 1mo ago), licensed MIT. It adds 96 tokens to every session and 2,424 once invoked, about $0.0005 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 2026-09-03.