Feature Doc Builder Skill

Startup Sequence

Before starting the dialogue:

1. Use AGENTS.md as the source of truth for repo-specific settings such as docs root, tracking system, project-code conventions, and documentation workflow rules. Read it if that context is not already available.
2. Identify whether you are creating a new feature document, evolving an existing one, or converting a transcript into a draft.
3. Find the standards index and any existing feature documents, feature roadmap notes, or project milestone references that should shape the discussion.
4. Then begin the dialogue and keep the conversation at feature scope rather than deliverable implementation scope.

Mission

Create or evolve a feature requirements document that explains a long-lived application capability at the product and system level.

The feature requirements document should help answer:

• why this feature exists
• what value it creates
• what is live today
• what still needs to be built
• how the feature should evolve through roadmap increments
• which project milestones or timeline windows the feature work may contribute to

This skill is for feature definition and feature evolution. It is not a deliverable-specification skill and it does not replace deliverable specification authoring.

It should help the Project Owner articulate feature-level success criteria and roadmap-increment outcomes that later inform deliverable acceptance criteria. If project milestones exist, treat them as project timeline context, not as feature-managed containers.

Primary Audience

Work primarily with:

• Project Owner
• Deliverable Owner when a planned delivery needs feature context
• stakeholders with domain context

Secondary audiences for the resulting feature requirements document:

• developers onboarding to the project
• the development team reviewing feature intent, roadmap increments, and project milestone context
• future agents that need product context before creating deliverable specifications

Docs Root Convention

Use the repo docs root declared in AGENTS.md, the standards index, or another repo-local orientation document as the base for Zazz methodology artifacts. Example paths in this skill may use <DOCS_ROOT>/... as shorthand.

Important: do not infer that a directory literally named docs/ is the docs root. Some repos use a Zazz root such as .zazz/, with .zazz/docs/ reserved for imported reference guides. In that layout, feature documents belong under .zazz/features/, not under .zazz/docs/features/.

What This Skill Produces

Primary artifact:

• <DOCS_ROOT>/features/{feature-key}.md

If the user provides an explicit feature document filename or path, that filename/path is sacrosanct. Use it exactly, normalized only for the repo's docs root when necessary. Do not replace it with a slug inferred from the feature title, domain language, an earlier draft title, or adjacent filenames.

Supporting discovery artifact:

• update <DOCS_ROOT>/features/index.yaml when the feature document is created or materially revised

Boundaries

This skill does

• define the feature's purpose, value, and current state
• capture feature-level success criteria and roadmap-increment outcomes
• capture system-level behavior and important user/system flows
• decompose feature evolution into roadmap increments
• identify what is live, planned, proposed, or deferred
• ingest transcripts or meeting notes and turn them into a feature document draft
• produce handoff guidance for later deliverable specifications

This skill does not

• write deliverable-level acceptance criteria for implementation tasks
• produce execution-ready task decomposition
• replace proposal analysis when the team is still deciding whether to pursue an idea
• implement the feature

Artifact boundaries:

• proposal-builder helps decide whether or how to proceed
• feature-doc-builder defines the long-lived feature and feature roadmap increments
• spec-builder defines one deliverable's execution contract

Interaction Modes

Mode A: Live Project Owner dialogue (default)

Use a conversational process with a Project Owner, Deliverable Owner, or stakeholder to draw out the feature's why, current state, and future roadmap increments.

Mode B: Transcript ingestion

If the user provides a transcript or meeting notes:

1. summarize the core problem, goals, and decisions
2. infer the feature's intent and current/planned states
3. identify open questions and missing roadmap-increment detail
4. generate or refresh the feature document draft

Mode C: Existing feature-document revision

When the user already has a feature document:

1. read the current feature document
2. identify what changed after the latest roadmap increment or discussion
3. update current-state sections, roadmap increment statuses, and flows
4. preserve long-lived feature intent while refreshing stale sections

Mode D: Development mode

If the user says "development mode" or equivalent, the focus is on improving this skill itself. In development mode, you may edit .agents/skills/feature-doc-builder/SKILL.md. Outside development mode, this file is read-only.

Human-Facing Usage Guidance

This is an interactive, back-and-forth skill.

The Project Owner does not need to provide a complete feature document up front. A strong starting prompt plus iterative dialogue is enough. The agent should:

• ask clarifying questions about the feature's value and current state
• help distinguish current behavior from planned future behavior
• help define or revise the next few meaningful feature roadmap increments
• draft the feature document early enough that the Project Owner can react to a concrete document

This skill should feel like a structured product-definition conversation, not a deliverable-specification session.

Example starter prompts

Example 1: New feature document

Use feature-doc-builder.
I want to create a feature document for role-based access control in our application.
This feature needs to explain why RBAC matters, what the system does today, what needs to be added, and how we should break it into roadmap increments.
Please guide me through this in a back-and-forth dialogue and draft the feature document as we refine it.

Example 2: Update an existing feature document after a roadmap increment

Use feature-doc-builder.
We already have a feature document for our billing feature, and roadmap increment 1 has shipped.
Please help me update the feature document so it reflects the current live behavior, marks roadmap increment 1 complete, and refines the next increments based on what we learned.

Example 3: Transcript-first feature-document drafting

Use feature-doc-builder.
I am pasting notes from a product and engineering meeting about a new approvals workflow.
Please infer the feature intent, current state, likely roadmap increments, related project milestone context, and open questions, then draft a feature document and ask follow-up questions where the discussion was ambiguous.

Prompt structure that works well

The best starting prompts usually include:

• the feature name
• why the feature matters
• what is known about the current state
• whether this is a new feature document or an update
• a request for iterative dialogue and drafting

Dialogue Principles

• Start with the problem and business/domain value before discussing solution shape.
• Keep the discussion at the feature level, not the deliverable-task level.
• Ask about current state explicitly. A feature document must describe what the application does today, not just the future vision.
• Distinguish what is live, planned, proposed, and deferred.
• Treat feature roadmap increments as meaningful increments of user or system value.
• Treat project milestones as project timeline containers that can contain deliverables from multiple features.
• Push back when the conversation collapses into low-level implementation detail that belongs in standards or deliverable specifications.
• Use transcripts as evidence, not truth. Surface inferred assumptions and ask for confirmation.

No padding

Every sentence, table row, diagram, and section must justify its presence. Do not:

• repeat the same point across sections to fill a template
• include user flows, use cases, or examples that cannot realistically occur (e.g. a UI flow that the UI itself prevents)
• include sequence diagrams or scenarios that describe behavior generic to every route or every feature rather than this specific feature
• pad out a section with boilerplate text to give it more apparent substance
• add sentences that summarize what the next section is about to say

If a sentence or section is removed and the document still answers the same questions equally well, the sentence or section was padding and should have been left out. Prefer a short, dense document over a long, repetitive one.

Required Inputs

Before drafting a serious feature document, elicit or infer:

1. feature name and feature key
2. explicit feature document filename/path, if the user provided one
3. problem statement
4. business/domain justification
5. who is affected
6. current state of the system
7. desired future state
8. major system concepts or entities involved
9. roadmap-increment breakdown or at least a first-pass feature roadmap model

If important inputs are missing, continue the dialogue and mark assumptions explicitly. If the user has provided a feature document filename/path and later wording seems to conflict with it, stop and ask for confirmation before creating, moving, renaming, or referencing a different feature document.

Standards and Feature Context Integration

Process:

1. Read <DOCS_ROOT>/features/index.yaml if it exists to avoid duplicating or overlapping an existing feature doc.
2. Read <DOCS_ROOT>/standards/index.yaml only as needed for system-level constraints that materially shape the feature.
3. Reference standards where they affect feature boundaries or roadmap-increment decomposition, but do not restate detailed implementation rules inside the feature document.

The feature document should stay product/system-oriented. Detailed coding conventions remain in standards. Deliverable-level test and execution detail remains in deliverable specifications.

Feature Document Content Requirements

Each feature document draft should usually include:

1. Feature title and summary
2. Current roadmap increment and next roadmap increment
3. Introduction / problem statement
4. Why this feature matters
5. Current state
6. Feature-level success criteria
7. Core concepts / domain model
8. User flows and system flows
9. Feature roadmap overview table
10. Roadmap increment detail sections with increment outcome criteria
11. Risks, constraints, and non-goals
12. Open questions
13. Deliverable handoff considerations

What "current state" means

The feature document must explain what the application actually does today as of the latest completed roadmap increment. This is one of the most important distinctions between a feature document and a proposal.

What "feature roadmap increment" means

A feature roadmap increment is a meaningful feature increment that advances the capability. It may identify one or more candidate deliverables, and those deliverables may later be slotted into one or more project milestones. The feature document should make the feature evolution intelligible to both stakeholders and the development team without turning project milestone dates or membership into feature-managed data.

Every roadmap increment must have all three of:

1. A timeline note. Use a related project milestone, target window, or TBD. Do not invent a project milestone date in the feature document when a project planning surface such as Zazz Board, Jira, GitHub Projects, or Confluence owns project milestone scheduling.
2. A capability statement. One sentence answering "at the end of this increment, what can the user or system do that it could not do before?"
3. A candidate deliverables list. The concrete shippable units (backend service, route, UI page, migration, etc.) that together produce the increment's capability. The list does not need to enumerate sub-tasks; that belongs in a deliverable specification.

When a roadmap increment ships, update the current-state sections and mark the increment complete. If a project milestone also closed, update the declared project milestone source of truth rather than duplicating that state in the feature document.

Feature documents do not define project milestones

The feature document is authoritative for feature purpose, current state, feature roadmap increments, capability statements, and feature-level success criteria. It may link to project milestones, but it does not define their names, dates, membership, or order.

Project milestones are project-scoped timeline containers. A single project milestone may contain deliverables from multiple features, and one feature roadmap increment may contribute deliverables to more than one project milestone when the project plan requires it. If a project milestone needs to be added, removed, renamed, rescheduled, or rescoped, the Project Owner updates the declared project milestone source of truth first.

Roadmap increments should be coherent sections

Each roadmap increment may get its own top-level (##) section when the feature is large enough to need that structure. Within that section, place everything specific to that increment: capability statement, increment-specific concepts, user flows, candidate deliverables, outcome criteria, and end-of-increment summary. Do not interleave content from multiple increments inside the same section. Cross-cutting material that genuinely applies across all increments (introduction, universal concepts, permissions catalog, roadmap overview, future topics, open questions) lives in dedicated sections before or after the per-increment sections. The result is that a reader can understand one roadmap increment without confusing it with a project milestone.

Feature-level success criteria vs deliverable acceptance criteria

At the feature document level, success criteria should describe value and system outcomes, not implementation tests. They answer questions like:

• what valuable capability exists after this roadmap increment?
• what should be true of the product when this feature is successful?
• what outcome should later deliverables prove through acceptance criteria and TDD?

Those feature-document-level success criteria should inform later deliverable acceptance criteria, but should not replace deliverable-level testability requirements.

Recommended Feature Document Sections

Use this section order unless the Project Owner explicitly asks for a different structure:

1. Title
2. Feature summary
3. Current roadmap increment / next roadmap increment / related project milestones / services affected
4. Introduction
5. Why this feature matters
6. Concepts
7. User flows and system flows
8. Feature roadmap overview
9. Roadmap increment detail sections
10. Current state summary
11. Planned future evolution
12. Open questions and follow-ups

Facilitator Question Bank

Problem and value

• What problem does this feature solve?
• Why is it necessary now?
• What business, user, or operational value does it add?
• What gets worse if we do not build this?

Current state

• What does the system do today in this area?
• What is already shipped?
• Where are the current pain points, workarounds, or gaps?

Domain and concepts

• What are the important nouns and concepts in this feature?
• Which actors or systems participate?
• What terminology should be stable in the feature document?

Flows

• What are the most important user flows?
• What are the key system flows behind them?
• Which flows differ across roadmap increments?

Feature roadmap and project milestones

• What is the smallest meaningful first feature roadmap increment?
• Which increments unlock visible user or system value?
• Which increments are backend-first, frontend-following, or cross-system?
• Which project milestones or timeline windows should these increments contribute to?
• Could one project milestone contain deliverables from this feature and other features?
• Which parts are definitely in scope now, and which should wait?

Handoff to deliverables

• Which roadmap increment slices are likely to become separate deliverables?
• Are there project milestone or timeline dependencies the spec-builder should know about later?
• Which parts require multiple deliverables rather than one large implementation?

Output Naming and Placement

Use methodology naming guidance:

• Feature requirements document: <DOCS_ROOT>/features/{feature-key}.md
• Features index: <DOCS_ROOT>/features/index.yaml

Filename authority rule:

• An explicit user-provided feature document filename or path wins over generated names.
• Do not infer a replacement filename from the feature title, a broad capability label, or a previous mistaken document name.
• If two filenames appear in the conversation or repo state, ask which one is canonical before editing paths, indexes, or downstream specification references.
• If the user explicitly renames the feature document, update the feature index and all downstream references in the same change.

Keep features/ flat by default: one feature key maps to one feature document. Do not create a sibling feature document for additional discussion about the same feature.

Only split a feature into subdocuments when the feature document itself becomes large enough to need it, typically around 700-800+ lines. Treat that range as a prompt to consider the structure, not as a mechanical line-count rule. If a split is needed, split by logical feature sections such as overview, user flows, feature roadmap, data model, integration notes, or open questions. Do not split by arbitrary line ranges.

When that happens, replace the file with a directory using the same feature slug:

<DOCS_ROOT>/features/{feature-key}.md

becomes:

<DOCS_ROOT>/features/{feature-key}/

Use numbered filenames so the directory listing stays organized. The entry point should be named 0-feature-summary.md, matching the first section of a normal feature document. It should orient readers to the feature and include a table of contents linking to the other section documents. Continue with logical section documents such as 1-user-flows.md, 2-feature-roadmap.md, or 3-data-model.md, using names that match the actual feature structure. The feature key and feature identity remain the same.

Generation Triggers

When the user says:

• "generate the feature document"
• "draft the feature doc"
• "write the feature requirements"
• "create a feature document"

...generate a draft immediately from the discussion so far, then iterate.

When the user says:

• "roadmap increment 1 is complete"
• "update the feature document"
• "refresh the feature doc"

...update the current-state and feature roadmap sections to reflect the new system reality.

Feature Document -> Deliverable Handoff

When the feature document is approved or a roadmap increment is ready for execution, provide a handoff package for later deliverable specification work containing:

1. feature key and feature document path
2. roadmap increment being implemented
3. related project milestone or target timeline, if known
4. current-state summary
5. desired roadmap-increment outcome
6. relevant flows and concepts
7. constraints and non-goals
8. likely deliverable slices

This handoff informs deliverable specification creation but does not replace spec-builder.

Quality Bar

A feature document draft is high quality when:

1. the feature's why is explicit and persuasive
2. the current state is accurate and not hand-wavy
3. the major concepts and flows are understandable to a new developer
4. roadmap increments are meaningful, ordered, and not just arbitrary task buckets
5. every roadmap increment has a timeline note, a one-sentence capability statement, and a candidate deliverables list
6. related project milestones are referenced as project-scoped timeline containers, not redefined as feature-managed milestones
7. the document helps both stakeholders and the development team
8. the handoff to later deliverables is clear without collapsing into implementation detail

Example Use Cases

• define a new long-lived capability before any deliverable specifications exist
• turn a stakeholder workshop transcript into a first feature document draft
• update a feature document after roadmap increment 1 ships
• decompose a feature into roadmap increments before creating individual deliverable specifications