version: "1.0.2" name: write-spec description: | Methodology for drafting technical design specs. Load when asked to write, draft, or refine a spec, design doc, architecture note, RFC, or similar document for a system, API, protocol, or subsystem. Also load when updating an existing spec, or moving one between lifecycle states. Also load FIRST when a file in context directs agents to load a spec-writing skill. metadata: maintainers: [bew]

Skill: write-spec

Goal

Produce structured, honest, maintainable technical specs capturing design decisions, interface shape, invariants, and open questions.

Entry gate

No spec file may be written before manage-spec init ran and printed $specpath. Phase:Discover owns that step. The only exception is a legacy layout, which starts with manage-spec migrate.

An approved plan or a settled design settles content only. It waives Phase:Explore, never Phase:Discover: the discovery notes still get written, and the section skeleton still gets confirmed.

A repo that already holds specs does not short-circuit the lifecycle. A legacy _WIP_SPECS/ or _SPECS/ layout goes through manage-spec migrate; never write a SPEC.md into it by hand.

Phases

Phases, in order (Explore is optional):

1. Phase:Discover — gather inputs; create the spec dir in discovery; capture the paths
2. Phase:Explore _(if design uncertain)_ — move to explo; delegate to design-exploration
3. Phase:Draft — promote to draft; confirm structure; write spec; fill sections iteratively
4. Phase:Review — in-context review; assess readiness; transition the spec

Vars supplied by the caller:

• $slug — short kebab-case identifier for this spec, confirmed in Phase:Discover
• $title — the spec's human-readable title

Vars printed by `manage-spec`:

• $slug — re-reported when rename changes it
• $specdir — the spec's own directory
• $specpath — the spec file to read and edit

init prints them first, and every command that moves or renames the spec re-reports them. Take them from the tool output; never derive them yourself.

The lifecycle tool is <skill-dir>/scripts/manage-spec; read <./refs/lifecycle.md>.

manage-spec prints a Session vars block listing the variables that changed — use what it prints, and keep values that did not change. Session vars: unchanged means every value stays as it was.

The spec's H1 carries a status tag: # [STATUS] <Title> Current status tags: DISCOVERY, EXPLO, DRAFT, MAYBE-READY, READY, ABANDONED. manage-spec owns the tag, the loader paragraph, and the directory name — never edit any of them, and never move a spec dir by hand.

Interaction conventions

Apply in every phase.

`tell me more`, `tell me about …`, or `explain …`: The user wants an explanation in chat output only — not a spec edit. Treat it as informational:

• Do not edit $specpath.
• Do not add Open Questions entries or change the status tag.
• Answer in chat, then pause and wait for the user to resume.

Whether anything is later folded into the spec is the user's explicit call.

Asking about Open Questions (via the question tool): The last message the user sees before the question batch must carry enough context to understand every question in it — the tool's own titles are easy to miss.

• Name the section and the OQ entry each question refers to.
• When one batch asks several OQs, contextualize all of them — not just the first.
• Never emit an OQ question call with no contextualizing message before it.

This applies to OQ asks only, not to every question batch.

1. Phase:Discover — Gather inputs & create the spec directory

When entering Phase:Discover: read <./refs/phases/discover.md> for full instructions.

2. Phase:Explore — Delegate deep design maturation _(if design uncertain)_

Optional phase. Delegate deep, pre-spec design maturation to the design-exploration skill. Enter when the design is genuinely uncertain — competing models, an undefined central concept. Skip straight to Phase:Draft when the design is settled enough to choose a section skeleton.

When entering Phase:Explore: read <./refs/phases/explore.md> for full instructions.

3. Phase:Draft — Write skeleton; fill sections iteratively

When entering Phase:Draft: read <./refs/phases/draft.md> for full instructions.

4. Phase:Review — In-context review pass

When entering Phase:Review: read <./refs/phases/review.md> for full instructions.