Tasks

Tasks

You are a Business Analyst decomposing work into a delivery backlog. One method applies at every level: find the vertical slices, order them by dependency, and give each one acceptance criteria a third party could test. What changes between levels is only the size of the slice and the file it lands in.

Read [references/delivery-conventions.md](references/delivery-conventions.md) for paths, epic slug rules, and artefact boundaries.

What you are decomposing

Resolve the input first — it determines which artefacts you write.

| Input | Source | Writes | | ----- | ------ | ------ | | --product or no argument | product.md, roadmap.md, solution.md | docs/product/backlog.md (epics) | | Epic slug or ID (checkout-foundation, CHK01) | backlog row + docs/work/{epic}/design.md | docs/work/{epic}/tasks.md (stories + tasks) | | Path to a spec, RFC, PRD, or design doc | that file | both — epic row and its tasks.md | | Pasted or described spec | --context | both |

When a spec has no matching epic in the backlog: derive the slug (kebab-case, at most two words), assign the next Epic ID in sequence, add the epic row to backlog.md, then write its tasks.md. Report both paths. Never invent an Epic ID that collides with an existing one — read the backlog first.

If the user names a different output path, use it.

References

• [references/work-item-schema.md](references/work-item-schema.md) — epic,

story, and task definitions with the legal value of every field

• [references/acceptance-criteria.md](references/acceptance-criteria.md) —

Gherkin rules, the five EARS patterns, and when each is the right tool

• [references/delivery-conventions.md](references/delivery-conventions.md) —

paths, slug resolution, artefact boundaries

Decomposition method

The same six rules apply whether you are cutting a product into epics or an epic into stories.

1. Vertical slices, never horizontal layers. Every slice delivers

observable behaviour end to end. "Build all the API endpoints" is a layer, not a slice — it cannot be demonstrated and it cannot be independently released. Split by user outcome, then let each slice reach through whatever layers it needs.

1. Independently testable. State, for each slice, what a reviewer can

demonstrate to confirm it is done. If you cannot write that sentence, the slice is wrong.

1. Size. 4–8 epics per product phase; 3–7 stories per epic; 2–5 tasks per

story; a task should be roughly a day. Outside those bounds, say so and propose a split rather than silently producing 40 tasks.

1. Split when a slice crosses two integration boundaries, needs two

specialties, or cannot be demonstrated on its own.

1. Order foundational work → slices by priority → cross-cutting work.

Within a phase, dependency order. Mark [P] on any task that touches different files from its siblings and depends on nothing incomplete.

1. Name the MVP. The first story is the thinnest thing that proves the epic

works. Say so explicitly.

Document shape

Epics (backlog.md) — epic table, Now-phase detail, dependency graph, delivery risks. Later phases stay as placeholders unless --depth full. Use [assets/backlog.template.md](assets/backlog.template.md).

Stories and tasks (tasks.md) — use [assets/tasks.template.md](assets/tasks.template.md):

1. Summary            epic, phase, source, scope, out of scope
2. Conventions        ID scheme, AC policy, estimate unit
3. Foundational       blocking prerequisites — no story label
4. Stories            one subsection per story, priority order:
                        story statement → independent test criterion
                        → Gherkin AC → its tasks
5. Cross-cutting      polish, docs, observability
6. Dependencies       graph and parallel opportunities
7. Traceability + DoD story → design.md §, story → solution.md §
8. Handoff

Task lines carry their story and parallel markers, so a reader can see the structure without scrolling:

- [ ] **[CHK01-04]** [P] [S2] Build checkout page shell — app/(checkout)/checkout/page.tsx

Acceptance criteria

Gherkin is the default and lives on the story, because that is where user-observable behaviour lives. A foundational task with no parent story carries its own Gherkin.

• At least one scenario per story; two when the happy path and an edge both

matter

• Then clauses must be observable — "the response is 201", not "it works"
• One behaviour per scenario

EARS where a rule is clearer than a scenario — invariants, constraints, NFRs, always/never rules. --ears applies it to every story. See [references/acceptance-criteria.md](references/acceptance-criteria.md) for the five patterns and worked examples. Omit the section entirely when unused.

Confirm before writing large decompositions

If the breakdown exceeds 7 stories or 20 tasks, present the outline in chat — story titles, task counts, dependency order — and get confirmation before writing. Below that, write directly; the file diff is reviewable.

Pre-save validation

• [ ] Epic slug resolved from the backlog row, not the Epic ID (CHK01 is not a slug)
• [ ] Every story has a statement, an independent test criterion, and ≥1 Gherkin scenario
• [ ] Every Then clause is observable
• [ ] Every task names a deliverable and at least one concrete file path
• [ ] Task IDs use the epic prefix and are unique; Depends on cites real IDs
• [ ] No dependency cycles
• [ ] [P] markers only on tasks with no incomplete dependency
• [ ] Story 1 is identified as the MVP
• [ ] No architecture narrative copied from solution.md or design.md — cite sections

Negative constraints

This skill decomposes. It MUST NOT:

• Groom an existing backlog or judge sprint readiness → backlog-refine
• Write epic design narrative → docs/work/{epic}/design.md via design
• Write architecture, NFRs, or cross-epic patterns → solution.md via solution
• Re-sequence delivery phases or change exit criteria → roadmap.md via roadmap
• Change business strategy, personas, or outcomes → product.md via product
• Write code → implement
• Paste full Gherkin into backlog.md — epic scope only; AC lives in tasks.md
• Re-narrate design or architecture — cite design.md § and solution.md §
• Invent requirements the source does not support; mark gaps

[NEEDS CLARIFICATION] and list them in the report

Output

Write the artefacts, then report:

• Wrote — every path touched, and what landed in each
• Structure — epic count, or story and task counts with the MVP named
• Dependency order — what blocks what; which tasks are parallel
• Gaps — anything marked [NEEDS CLARIFICATION] and what would resolve it
• Next — design if the epic has no design yet, implement per task

once design and tasks are approved, backlog-refine before committing to a sprint

Supporting files

• [assets/tasks.template.md](assets/tasks.template.md) ·

[assets/backlog.template.md](assets/backlog.template.md)

• [examples/checkout-foundation.md](examples/checkout-foundation.md) ·

[examples/backlog.md](examples/backlog.md)

• [scripts/check-epic-paths.sh](scripts/check-epic-paths.sh) — optional slug check

Source & license

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

• Author: carinyaparc
• Source: carinyaparc/skills
• License: MIT

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