user-story skill

Purpose

Create clear, concise user stories that combine Mike Cohn's user story format with Gherkin-style acceptance criteria. Use this to translate user needs into actionable development work that focuses on outcomes, ensures shared understanding between product and engineering, and provides testable success criteria.

This is not a feature spec—it's a conversation starter that captures who benefits, what they're trying to do, why it matters, and how you'll know it works.

Input

Works best with: The feature or user need the story captures. Also useful: The user role, the outcome they want, and edge cases the acceptance criteria must cover.

Anything supplied with the invocation itself — text after the skill name, a pasted context dump, or an appended ARGUMENTS: line — counts as answers already given. Use it and skip whatever it covers; don't re-ask.

Arriving empty-handed? That works too. The skill asks who the user is and what they're trying to accomplish before drafting story and Gherkin criteria.

Example invocation: Write user stories for password reset via SMS for our banking app — include the lockout edge case.

Key Concepts

The Mike Cohn + Gherkin Format

A user story combines:

Use Case (Mike Cohn format):

• As a [user persona/role]
• I want to [action to achieve outcome]
• so that [desired outcome]

Acceptance Criteria (Gherkin format):

• Scenario: [Brief description of the scenario]
• Given: [Initial context or preconditions]
• and Given: [Additional preconditions]
• When: [Event that triggers the action]
• Then: [Expected outcome]

Why This Structure Works

• User-centric: Forces focus on who benefits and why
• Outcome-focused: "So that" emphasizes the value delivered, not just the action
• Testable: Gherkin acceptance criteria are concrete and verifiable
• Conversational: Story is the opening for discussion, not the final spec
• Shared language: Product, engineering, and QA all understand the format

Anti-Patterns (What This Is NOT)

• Not a task: "As a developer, I want to refactor the database" (this is a tech task, not user value)
• Not a feature list: "I want dashboards, reports, and analytics" (this is too big—needs splitting)
• Not vague: "I want a better experience" (unmeasurable, no clear outcome)
• Not a contract: Stories are placeholders for conversation, not locked-in specs

When to Use This

• Translating user needs into development work
• Backlog grooming and sprint planning
• Communicating value to engineering and design
• Ensuring testable acceptance criteria exist before development

When NOT to Use This

• For pure technical debt or refactoring (use engineering tasks instead)
• When stories are too large (split first—see skills/user-story-splitting/SKILL.md)
• Before understanding the user problem (write a problem statement first)

Application

Step 1: Gather Context

Before writing a story, ensure you have:

• User persona: Who is this for? (reference skills/proto-persona/SKILL.md)
• Problem understanding: What need does this address? (reference skills/problem-statement/SKILL.md)
• Desired outcome: What does success look like?
• Constraints: Technical, time, or scope limitations

If missing context: Run discovery interviews or problem validation work first.

Optional Helper Script (Template Generator)

If you want a consistent Markdown stub, you can generate one from CLI inputs. This script is deterministic and does not fetch data or write files.

python3 scripts/user-story-template.py --persona \"trial user\" --action \"log in with Google\" --outcome \"access the app without creating a new password\"

Step 2: Write the Use Case

Use template.md for the full fill-in structure.

Fill in the template:

### User Story [ID]:

- **Summary:** [Brief, memorable title focused on value to the user]

#### Use Case:
- **As a** [user name if available, otherwise persona, otherwise role]
- **I want to** [action user takes to get to outcome]
- **so that** [desired outcome]

Quality checks:

• "As a" specificity: Is this a specific persona (e.g., "trial user") or generic ("user")?
• "I want to" clarity: Is this an action the user takes, or a feature you're building?
• "So that" outcome: Does this explain the user's motivation? Or is it just restating the action?

Common mistakes:

• ❌ "As a user, I want a login button, so that I can log in" (restating the action)
• ✅ "As a trial user, I want to log in with Google, so that I can access the app without creating a new password"

Step 3: Write the Acceptance Criteria

Fill in the template:

#### Acceptance Criteria:

- **Scenario:** [Brief, human-readable scenario describing value]
- **Given:** [Initial context or precondition]
- **and Given:** [Additional context or preconditions]
- **and Given:** [Additional context as needed]
- **and Given:** [UI-focused context ensuring 'When' can happen]
- **and Given:** [Outcomes-focused context ensuring 'Then' is delivered]
- **When:** [Event that triggers the action—aligns with 'I want to']
- **Then:** [Expected outcome—aligns with 'so that']

Quality checks:

• Multiple Givens are okay: Preconditions stack up (e.g., "Given I'm logged in" + "Given I have items in my cart")
• Only one When: If you need multiple "When" statements, you likely have multiple stories—split them
• Only one Then: If you need multiple "Then" statements, you likely have multiple stories—split them
• Alignment: Does "When" match "I want to"? Does "Then" match "so that"?

Red flags:

• Multiple Whens/Thens: Sign of scope creep—split the story (reference skills/user-story-splitting/SKILL.md)
• Vague Thens: "Then I see improved performance" (unmeasurable—make it specific)

Step 4: Add a Summary

Write a short, memorable summary that captures the story's value:

- **Summary:** [Brief, human-readable title]

Examples:

• ✅ "Enable Google login for trial users to reduce signup friction"
• ✅ "Bulk delete items to save time for power users"
• ❌ "Add delete button" (feature-centric, not value-centric)

Step 5: Validate and Refine

• Read aloud to the team: Does everyone understand who, what, why?
• Test acceptance criteria: Can QA write test cases from this?
• Check for splitting: If the story feels too big, use skills/user-story-splitting/SKILL.md
• Ensure testability: Can you prove "Then" happened?

Examples

See examples/sample.md for full examples (good, bad, and split-needed stories).

Mini example excerpt:

### User Story 042:

- **Summary:** Enable Google login for trial users to reduce signup friction

#### Use Case:
- **As a** trial user visiting the app for the first time
- **I want to** log in using my Google account
- **so that** I can access the app without creating and remembering a new password

#### Acceptance Criteria:
- **Scenario:** First-time trial user logs in via Google OAuth
- **Given:** I am on the login page
- **and Given:** I have a login account
- **When:** I click the "Sign in with Google" button and authorize the app
- **Then:** I am logged into the app and redirected to the onboarding flow

Common Pitfalls

Pitfall 1: Technical Tasks Disguised as User Stories

Symptom: "As a developer, I want to refactor the API, so that the code is cleaner"