breakdown

breakdown is a skill for Claude Code, Codex from int2t05/engineering-skills. It costs 76 tokens per session (1,400 once invoked), scanned A, original, MIT.

A skill for turning an approved plan or specification into small, ordered work tickets. Each ticket describes a complete slice of work and what must be decided or finished first.

In plain words
What is it for?
Use it to decompose a project into implementation tickets, map decisions across multiple sessions, and order work across areas such as data, APIs, interfaces, and tests.
Why use it?
It makes larger changes easier to sequence and shows which decisions or tasks are blocking later work.

Skill for Claude CodeCodex

Installs and runs on its own, but its text points at files inside its plugin — anything it tells you to read at a ${CLAUDE_PLUGIN_ROOT} path is only there once the plugin is installed. Installing the plugin gets both.

Part of the engineering-skills plugin — 48 skills, 1 agent, 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/int2t05/engineering-skills/breakdown
Any agent
npx skills add int2t05/engineering-skills --skill breakdown
Clone the repo
git clone --depth 1 https://github.com/int2t05/engineering-skills

Made for: Claude Code, Codex.

Or install engineering-skills, the plugin that ships this one along with the rest of its 48 skills, 1 agent, 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 breakdown

README.md
[![agentmods](https://agentmods.dev/badge/skills/int2t05/engineering-skills/breakdown.svg)](https://agentmods.dev/skills/int2t05/engineering-skills/breakdown)
Your own site
<a href="https://agentmods.dev/skills/int2t05/engineering-skills/breakdown"><img src="https://agentmods.dev/badge/skills/int2t05/engineering-skills/breakdown.svg" alt="Measured on agentmods" height="20"></a>
Per session 76 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,400 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 $0.00076 $0.01400
Opus 5 $0.00038 $0.00700
Sonnet 5 $0.00015 $0.00280
Haiku 4.5 $0.00008 $0.00140

Measured 5d ago against content hash 42d4e4433356, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

breakdown 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 5d 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.

skills/04-develop/breakdown/SKILL.md · 113 lines

How it starts

The opening of the file, as written. The whole thing — 113 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Breakdown

The plan itself comes from Claude Code's built-in plan mode (engineering-principles §7). This skill breaks the result into tickets.

Two modes. For work that fits one session, break it into tracer-bullet tickets with blocking edges. For work too large for one session, chart a decision map — a shared index of decision tickets resolved one at a time until the way to the destination is clear.

When to use

  • You have an approved plan, spec, or conversation result to break into tickets.
  • The work spans multiple sessions and needs a shared decision map.
  • You need to sequence work by blocking edges before implementation starts.

Not for: Work that fits one session (just implement it); writing the spec itself (use spec).

Steps

Mode 1 — Tracer-bullet tickets (work fits one session)

  1. Gather context. Read the plan or spec. If the user passes a reference (path, issue number, URL), fetch its full body. Explore the codebase if you haven't, so ticket titles use the project's domain glossary and respect existing ADRs.

  2. Draft vertical slices. Each slice cuts a narrow but COMPLETE path through every layer (schema, API, UI, tests) — vertical, not a horizontal layer. A completed slice is demoable on its own. Size each to a single fresh context.

  3. Declare blocking edges. For each ticket, list the tickets that must complete before it can start. A ticket with no blockers starts immediately.

  4. Wide-refactor exception. A single mechanical change fanning across the codebase (rename a column, retype a shared symbol) can't land green as a vertical slice. Sequence it as expand–contract: add the new form beside the old, migrate call sites in per-package batches (each its own ticket blocked by the expand), then delete the old form in a final ticket blocked by every batch.

  5. Quiz the user. Present the breakdown as a numbered list — title, blocked by, what it delivers. Ask: granularity right? Blocking edges correct? Any tickets to merge or split? Iterate until approved.

Read the full file on GitHub · 113 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago First seen · 113 lines · 76 tokens per session scan A 42d4e4433356

Subscribe to this mod's changes

breakdown is a skill published in the GitHub repository int2t05/engineering-skills (3 stars, last pushed 4d ago), licensed MIT. It adds 76 tokens to every session and 1,400 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 2026-08-31.