# Task Decomposer

> Use when converting a freeform feature request, ticket URL, PRD, or epic into structured TASK-NNN entries in TODO.md. Enforces an assumption registry, risk scoring, vertical-slice granularity, and validation before writing. Self-contained, no specialist agents. Do not use when a task already exists and is ready to build — use /orchestrator instead.

- **Type:** Skill
- **Install:** `agentstack add skill-aldianriski-lean-flow-task-decomposer`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [aldianriski](https://agentstack.voostack.com/s/aldianriski)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [aldianriski](https://github.com/aldianriski)
- **Source:** https://github.com/aldianriski/lean-flow/tree/main/skills/task-decomposer

## Install

```sh
agentstack add skill-aldianriski-lean-flow-task-decomposer
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Task Decomposer

Translate any form of human intent into fully-formed `TASK-NNN` entries. The approved output
serves as the scope gate — no separate gate runs after approval.

## Input types

| Input | Detection |
|---|---|
| Freeform — `"add Google OAuth login"` | no URL, no `--` flag |
| Ticket — `JIRA-123` or a Linear/GitHub URL | matches `[A-Z]+-[0-9]+` or a URL |
| PRD — `--prd docs/feature.md` | `--prd` flag + path |
| Epic — `--epic "Payments"` | `--epic` flag + name |

For a ticket, fetch the description first (ask the user to paste if credentials are missing — never block on env vars).

## Procedure

1. **Clarify — the grill** *(freeform / ticket only)* — ambiguity is cheapest to kill at intake. Ask ONE question at a time, each with a recommended answer; explore the codebase before asking. For mature / unfamiliar code, **recon first via the `Explore` agent** (existing impl + tests + deps → a tight brief, in its own context — a cheap-tier `sonnet` pass; the grill itself stays on the session model. Tier map → `CONTEXT.md`). Moves:
   - **Challenge the glossary** — a term conflicts with `CONTEXT.md`? Surface it: "your glossary says X, you seem to mean Y — which?"
   - **Sharpen fuzzy language** — replace an overloaded word ("account", "user") with a precise canonical term; feed a newly-pinned term straight to `/lean-doc-generator` (glossary), don't batch.
   - **Invent edge-case scenarios** — concrete cases that force the boundaries between concepts to be made explicit.
   - **Cross-reference code** — a claim contradicts the code? Surface the contradiction.
   - **A design that must be *felt*, or a high-stakes fork** — don't resolve it here: record it on the task (`assumes:`) so G2 routes to `/prototype` / `/council`.

   Stop when the goal is unambiguous. **Synthesize from context instead of re-interviewing ONLY when step 2's registry comes back with zero open assumptions** (a design discussion just happened and nothing is open); otherwise grill the open ones.
2. **Assumption registry** — list every assumption that affects behavior (auth model, data shape, third-party limits). Confirm the risky ones explicitly.
3. **Decompose into tracer-bullet vertical slices** — each task is a thin path through *every* layer end-to-end (schema → API → UI → tests), independently demoable. Prefer many thin slices over few thick ones; record `depends-on`. Horizontal layers ("write all the models", "all the tests") are NOT valid tasks.
4. **Risk score** — per task, rate impact × likelihood (low / med / high); note the blast radius (files / layers touched).
5. **Classify HITL / AFK** — `HITL` = a human must review the output before proceeding; `AFK` = autonomous completion is safe (acceptance is mechanically checkable · no irreversible side effects · no product/UX judgment call · spec is durable). Default to `HITL` when uncertain. **For `AFK` tasks, spec durably** — an AFK task may sit in the backlog for weeks before an agent picks it up: write behavioral contracts (name the types / interfaces / config shapes to change) + testable acceptance + explicit out-of-scope; **never reference file paths or line numbers** — they go stale.
6. **Validate** — every task has an observable acceptance criterion ("done when …"); no two tasks share identical criteria (merge or differentiate). For multi-slice breakdowns, run the **breakdown quiz** (reference) — confirm granularity, dependencies, merge/split, HITL/AFK — before Write.
7. **Write** — only after the human types `approve`, append entries to `TODO.md` **Backlog** in dependency order (blockers first). Touch no other file. Sprint formation happens later via `/lean-doc-generator promote`.

## Task entry shape

```
- [ ] TASK-042 —   [size: M] [risk: med] [HITL]
      done-when: 
      touches: 
      assumes: 
      state:   ready | needs-info   (set ready only if done-when is concrete)
```

Set the initial `state:` (`ready` if the done-when is concrete, else `needs-info`). Re-prioritising,
re-stating, and pruning the backlog later is `/triage`'s job — don't re-rank existing tasks here.

**Large features / `--prd`**: synthesize a PRD first (Problem · Solution · exhaustive User Stories ·
Implementation + Testing Decisions · Out-of-scope · seams), get approval, then decompose. Full PRD
template + seams + the breakdown quiz → `${CLAUDE_SKILL_DIR}/references/prd-and-slices.md` (`${CLAUDE_SKILL_DIR}` resolves to this skill's install directory at load time). Output is
local (TODO.md Backlog) — no external issue tracker.

## Hard rules

- Never write to `TODO.md` before the human types `approve`.
- After `approve`: Backlog only; never write directly into an Active Sprint.
- Identical acceptance criteria on two tasks → merge or differentiate first.
- A task with no observable acceptance criterion fails validation — rewrite it.
- A question that BLOCKS scope/design is asked here (one at a time) or recorded as an explicit `needs-info`/`blocked` with its unblock condition — never parked as a silent `assumes:` or a passive doc note that stalls dev.

## Red flags

| Rationalization | What it actually means |
|---|---|
| "I'll guess the acceptance criteria" | "works correctly" fails validation — write the observable outcome |
| "Skip the assumption registry, it's small" | unconfirmed auth assumptions are the top source of regressions |
| "Four questions at once is faster" | stacked questions get vague answers — one at a time forces precision |
| "These two are related, I'll merge them" | related ≠ same concern — verify the criteria are truly identical |
| "I'll slice it by layer" | horizontal layers aren't demoable — slice vertically |
| "A multiple-choice question pins the term" | an MCQ captures a *preference*, not a *definition* — pin a domain term with a concrete example, then confirm (L-017) |

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [aldianriski](https://github.com/aldianriski)
- **Source:** [aldianriski/lean-flow](https://github.com/aldianriski/lean-flow)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-aldianriski-lean-flow-task-decomposer
- Seller: https://agentstack.voostack.com/s/aldianriski
- Browse the marketplace: https://agentstack.voostack.com/browse

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