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Collaborative workflow for producing the three specification artifacts (intent, architecture notes, acceptance criteria) that describe a change and its goals before any implementation begins. Use when starting any new feature or behavior change — do not write code until artifacts pass the consistency gate. BDD/Gherkin scenarios are authored later, per slice, in /plan.

bdfinst By bdfinst schedule Updated 6/6/2026

name: specs description: Collaborative workflow for producing the three specification artifacts (intent, architecture notes, acceptance criteria) that describe a change and its goals before any implementation begins. Use when starting any new feature or behavior change — do not write code until artifacts pass the consistency gate. BDD/Gherkin scenarios are authored later, per slice, in /plan. role: worker user-invocable: true

Agent-Assisted Specification

Step 0 — Existing-spec version check

Before drafting or updating a spec, check whether a spec file already exists for this feature:

  • If no spec file exists: proceed directly to Step 1.
  • If a spec file exists: read its opening lines and check for a <!-- spec-version: --> comment or a **Format:** header field.
    • If the marker is absent or predates the current skill version (see frontmatter version:): surface this to the user — "An existing spec was found but appears to use an older format. Regenerate from scratch, or confirm you want to update in place?" — and wait for explicit direction before proceeding.
    • If the marker matches the current version: proceed to Step 1 with the existing file as base.

This prevents silently overwriting a current spec and catches format drift before the plan phase consumes stale artifacts. Produce three specification artifacts collaboratively with the human before any implementation begins. The spec describes the change and its goals; it does not define Gherkin scenarios — those are authored per slice during /plan. The consistency gate is a hard stop; do not proceed to planning until it passes.

Rules

  1. No implementation during specification. No code, no tests, no infrastructure until the consistency gate passes.
  2. One feature per specification. A spec describes a single coherent change end-to-end. Vertical slicing is deferred to /plan — do not slice here. Split into separate specs only when the request bundles genuinely unrelated features (see Scope Split Protocol).
  3. Consistency gate is a hard stop. Conflicts caught now cost minutes; conflicts caught during implementation cost sessions.
  4. Behavior contracts are authored in the plan. The spec sets intent, architecture constraints, and acceptance criteria. /plan turns those into per-slice Gherkin scenarios — the single source of truth for expected behavior. No implementation without a scenario; no scenario without an acceptance test.
  5. Max 2 critique-refine iterations per artifact. If it doesn't stabilize, escalate to the Orchestrator.
  6. Preserve human language when refining. The human owns the specification; the agent improves precision.
  7. Structured critique output. Categorize every critique (gap, ambiguity, conflict, scope violation) with a specific reference to the artifact text.
  8. Document decisions, not just outcomes. When the human rejects an agent suggestion, note why — prevents the same suggestion from recurring.

Artifacts

Artifact Purpose Format
Intent Description What the change achieves and why Plain language, 1–3 paragraphs
Architecture Specification Where the change fits and what constraints apply Structured notes: components, interfaces, dependencies, constraints
Acceptance Criteria Observable outcomes and quality thresholds that define "done" Measurable criteria with pass/fail conditions

Observable user behavior is captured as Gherkin in /plan, one scenario set per slice. The spec's job is to make that authoring unambiguous, not to pre-write it.

Collaboration loop

Every artifact follows the same loop:

  1. Human drafts based on current understanding.
  2. Agent critiques — categorize each finding as gap, ambiguity, conflict, or scope violation, with a specific reference.
  3. Human decides — accept, reject, or modify.
  4. Agent refines — produce an updated version incorporating decisions.

Repeat up to 2 iterations before escalating.

Critique categories

Category Description
Gaps Missing acceptance criteria, unstated assumptions, undefined behavior
Ambiguities Statements two implementers would interpret differently
Conflicts Contradictions between artifacts or with existing system behavior
Scope violations Spec bundles unrelated features that belong in separate specs

Ambiguity Resolution Protocol

After critiquing the artifacts but before writing the final acceptance criteria, run this protocol on every gap and ambiguity finding. This is a hard step — it cannot be skipped.

For each gap or ambiguity:

Step A — Attempt inference. Look for a reliable basis: existing codebase behavior, domain conventions, similar precedents in the system, or unambiguous implication from stated requirements.

Step B — Classify the finding.

Class Meaning Action
inferable A reasonable developer, given the codebase and domain, would make the same choice Document the inference and its rationale; proceed
requires-stakeholder-input The decision depends on product or business intent not evident from context; two reasonable developers would choose differently Block — ask the human before proceeding

Step C — Resolve requires-stakeholder-input items. Collect all such items and present them as a single batch to the human before writing acceptance criteria:

"Before writing acceptance criteria, I need clarification on N decisions the spec leaves open: [list]"

Wait for answers. Only then finalize the criteria.

What "inferable" is NOT: a convenient default. Naturalness or simplicity does not make a decision inferable — the test is whether a developer working from context alone would reliably land on the same answer. If in doubt, classify as requires-stakeholder-input.

Record every classification in an ## Ambiguity Log section of the spec file (see Output below). This log is the audit trail that turns "we asked before building" from an assertion into an artifact.

This protocol exists because the most common failure mode of spec synthesis from a vague prompt is writing decisions that look thorough while encoding the same happy-path assumptions a direct implementation would make silently. The log prevents that by making every assumption visible and every gap either resolved by the human or documented as inferable with explicit rationale.

Scope signals

A specification bundles too much when any of these fire:

  • Specification effort exceeds a short conversation.
  • More than ~5 components are affected.
  • Genuinely unrelated features are described (not just multiple slices of one feature).
  • The features described would not ship or be validated together.

Note: a single feature that decomposes into several deliverable increments is normal and expected — that decomposition happens in /plan, not here. Only split the spec when the features are independent.

Scope Split Protocol

  1. Identify the unrelated features bundled into the request.
  2. Propose a split into separate specs, one per feature.
  3. Human approves the split before specification continues on any feature.
  4. Each feature gets its own full set of three artifacts.

Cross-Artifact Consistency Gate

Validate all three artifacts as a set:

  • Intent is unambiguous — two developers would interpret it the same way.
  • Every behavior or goal in the intent maps to at least one acceptance criterion.
  • Architecture specification constrains implementation to what the intent requires, without over-engineering.
  • Same concepts are named consistently across all three artifacts.
  • No artifact contradicts another.
  • Every gap and ambiguity finding is logged — either documented as inferable (with explicit rationale) or resolved via explicit stakeholder input. No finding is left as an undocumented assumption.

Hard stop: do not proceed to planning until every item passes. The ambiguity log item is the most critical: a passing gate with undocumented assumptions produces false confidence.

Output

Three artifacts (Intent, Architecture Specification, Acceptance Criteria) plus a consistency gate pass/fail verdict. Be concise — flag gaps and conflicts; do not narrate the collaboration process.

Persist to file

After the gate passes, write all three artifacts plus the verdict to a markdown file. Downstream commands (/plan, /build, spec-compliance-review) find the spec via this file — chat-only specs are lost between sessions.

  1. Slugify the feature name: lowercase, replace spaces with hyphens, strip special characters. ("User Login with MFA" → user-login-with-mfa)
  2. Create docs/specs/ if missing.
  3. Check whether docs/specs/<slug>.md already exists. If yes, ask: overwrite or create a versioned file (<slug>-v2.md)?
  4. Write using this structure:
# Spec: <Feature Name>

## Intent Description
<intent artifact>

## Architecture Specification
<architecture artifact>

## Acceptance Criteria
<acceptance criteria artifact>

## Ambiguity Log

All gap and ambiguity findings from the Ambiguity Resolution Protocol, with their classifications and rationale.

| Decision | Classification | Resolved By | Rationale / Answer |
|----------|---------------|-------------|-------------------|
| <decision text> | `inferable` / `requires-stakeholder-input` | inference / human | <rationale or human's answer> |

## Consistency Gate
- [x/  ] Intent is unambiguous
- [x/  ] Every behavior/goal maps to an acceptance criterion
- [x/  ] Architecture constrains without over-engineering
- [x/  ] Terminology consistent across artifacts
- [x/  ] No contradictions between artifacts
- [x/  ] Every gap/ambiguity finding is logged — inferable with rationale or resolved by human
  1. Print the file path to chat so the user can find it.

Auto-trigger /plan

After persisting, automatically invoke /plan with the feature description. The plan command discovers the spec artifacts, decomposes the feature into vertical slices, and authors the Gherkin scenarios for each slice. Do not ask first — the approved spec is the trigger.

Install via CLI
npx skills add https://github.com/bdfinst/agentic-dev-team --skill specs
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