User Story Writer Skill

This skill produces production-ready user stories from a feature brief, PRD section, or verbal description. Each story follows the standard format with a clear who/what/why, behavioural acceptance criteria in Given/When/Then format, edge cases, and definition of done. Output is ready to paste into Jira, Linear, or your planning tool.

Required Inputs

Ask the user for these if not provided:

• Feature or change to break into stories — paste the brief, PRD section, or describe the feature
• User types / personas involved (e.g. admin, end user, guest, API consumer)
• Scope — are we writing one story or decomposing an epic into a full set of stories?
• Acceptance criteria format preference — Given/When/Then, bullet checklist, or both?
• Technical constraints or notes — anything the engineering team has flagged that should shape the stories

Output Structure

For each story:

Story: [Short title — verb + noun, e.g. "Filter search results by date range"]

Epic: [Parent epic name — e.g. "Advanced Search"] Story ID: [Jira/Linear ID — leave blank if not yet created] Priority: [P1 / P2 / P3] Story points: [Leave blank — for engineering to estimate]

User Story

As a [specific user type — not "user"], I want to [concrete action they want to take], So that [the outcome they achieve — business value, not feature description].

Example:

As an account manager, I want to filter my client list by last contact date, so that I can quickly identify clients I haven't spoken to in over 30 days and prioritise outreach.

Context

[1–3 sentences of context that aren't in the user story itself: when does this story matter, what triggers the need, how does it fit into a larger flow. This helps engineers understand why before they ask.]

Acceptance Criteria

Format: Given / When / Then

Each criterion tests one specific behaviour. Write one GWT per observable outcome — not one GWT for the whole feature.

AC1: [Short name for this criterion]

Given [starting state or context]
When [user action]
Then [observable system behaviour]

AC2: [Short name]

Given [...]
When [...]
Then [...]

AC3: [Short name]

Given [...]
When [...]
Then [...]

Edge Cases

[List scenarios that are non-obvious but must be handled. These become additional ACs or notes to engineering.]

• [Edge case 1]: [e.g. User applies a date filter that returns 0 results — show empty state with clear messaging and a "clear filters" action]
• [Edge case 2]: [e.g. User has >10,000 clients — filter must not degrade load time >200ms]
• [Edge case 3]: [e.g. Date filter persists across page refresh — or explicitly should not if that's the decision]
• [Permission edge case]: [e.g. Read-only users can see the filter but cannot save filter presets]

Out of Scope

[Explicitly state what this story does NOT cover — prevents scope creep and clarifies where the next story begins.]

• Saving and sharing filter presets (separate story — see [Story X])
• Bulk actions on filtered results
• Exporting filtered client list to CSV

Definition of Done

• Acceptance criteria all pass
• Edge cases handled (or explicitly deferred with a new ticket raised)
• Unit tests written for each AC
• Works on mobile viewport (if applicable)
• Accessibility: keyboard navigable and screen-reader compatible
• Error states are handled and copy approved
• Product and design have reviewed in staging
• No console errors in production build

Epic Decomposition Template

If the user provides an epic or feature brief, decompose it into a full set of stories before writing them:

Epic: [Name] Goal: [What outcome does completing this epic achieve?] Stories:

Suggested sprint order: [Which stories are P1 for MVP? Which can follow in a later sprint?]

Common Story Anti-Patterns — and Fixes

Use these to review stories before handing to engineering:

Example: Full Story Set for a Feature

Feature brief: "Allow users to export their invoice history as a PDF or CSV"

Story 1: Export invoice list as CSV

As a finance admin, I want to export my invoice history as a CSV file, so that I can import it into our accounting software without manual data entry.

AC1: Successful export

Given I am on the Invoices page with at least one invoice
When I click "Export" and select "CSV"
Then a CSV file is downloaded containing all visible invoices with columns: Invoice ID, Date, Amount, Status, Customer Name

AC2: Empty state

Given I am on the Invoices page with no invoices
When I click "Export"
Then the export button is disabled and a tooltip reads "No invoices to export"

AC3: Filtered export

Given I have applied a date filter showing invoices from Jan 2026 only
When I click "Export" and select "CSV"
Then the export contains only invoices from Jan 2026 — not all invoices

Edge cases:

• Export with >10,000 invoices — must complete in <30s or show a progress indicator
• Export triggered on mobile — downloads to device's default download location

Out of scope: PDF export (Story 2), scheduled exports (future epic)

Story 2: Export invoice list as PDF

As a finance admin, I want to export my invoice history as a formatted PDF, so that I can share a professional summary with our accountant.

[... ACs follow same pattern ...]

Quality Checks

• Every story has a specific user type — not "a user" or "the system"
• The "so that" explains business value — not just feature description
• Each AC tests one observable outcome — not a bundle of behaviours
• Empty states, error states, and edge cases are explicitly handled
• Out of scope is documented — not assumed
• Stories are independent — they can be shipped individually without depending on unreleased work (except where explicitly noted)

Anti-Patterns

• Do not write user stories from a technical perspective — every story must be from the user's point of view and state their goal
• Do not write acceptance criteria that are untestable — every criterion must have a clear pass/fail condition
• Do not create stories that are too large to complete in a single sprint — break epics into estimable, independently deliverable stories
• Do not omit edge cases — unhappy paths and error states are required, not optional
• Do not skip the Definition of Done — without it, "done" means different things to different people

Example Trigger Phrases

• "Write user stories for [feature] from this brief"
• "Break this PRD section into user stories with acceptance criteria"
• "Convert these feature requirements into Jira tickets"
• "Write the user stories and ACs for [feature name]"
• "Decompose this epic into individual stories ready for sprint planning"