Mission Define

Mission Define

Authors the first-write of project/mission.md against spec/project/mission/<canonical_language>.md (canonical language: English). The spec is the authority for the on-disk shape; this skill is the interactive front-end that fills it in.

German trigger phrases

This skill also triggers on equivalent German-language requests, including:

• "Mission definieren"
• "die SMART-Mission formulieren"
• "Mission-Datei aufsetzen"

Why this is a skill, not an agent

• Persistent on-disk artefact — the output is a versioned markdown file consuming skills (mission-revise, future audits, the roadmap layer) read for years to come; a skill owns persistent state, an agent returns a structured report and forgets.
• Mid-flow user gating is the SMART contract — every letter of SMART is a per-step user dialogue (audience choice, verifying-feature pointer, MVP scope size, outcome list, time-bound shape); the spec forbids batched output, so an agent's fire-and-forget shape would lose the gates.
• Output flows back into the main conversation — the audience tailoring paragraphs and the verifying-feature reference must surface in the conversation so the user can iterate before the file is written; isolating them behind an agent's structured-report boundary would obscure the iterative drafting.
• Counter-dimension considered: a narrower agent prompt could sharpen SMART-statement phrasing, but the load-bearing dimension here is interactivity (every SMART letter requires confirmation), not prose specialisation — skill wins.

User-language policy

Detect the user's language and respond in it. The mission file's mission_statement and per-audience paragraphs are written in the project's primary language (follow the precedent of existing artefacts in project/, defaulting to English when no precedent exists). Frontmatter keys, enum values, audience identifiers, outcome IDs, and feature-acceptance references stay in their canonical English form regardless of the user's language.

Preconditions

Before any drafting work:

• Confirm the working directory is the target project root (git rev-parse --is-inside-work-tree).
• Confirm git is reachable in PATH; the ## Source audit trail in operation 4 captures the audience artefact's last-commit SHA via git log and the mission write fails without it.
• Confirm project/mission.md does not yet exist. If it does, stop and tell the user this skill is first-write only — mission-revise owns edits.
• Confirm project/goals.md exists and parses (Vision section plus O-<n> outcomes per the sibling roadmap spec). If absent or empty, stop and ask the user to author goals first; outcomes are an input to mission Relevant, not something this skill invents.
• Confirm the audience artefact exists at the location declared by audience-identification (typically AUDIENCES.md). If absent, dispatch audience-identify first; the spec forbids inventing audiences inline.
• Confirm at least one feature under project/features/ exists with an acceptance-<n> criterion that can serve as the mission-verifying criterion. If none exists, stop and ask the user whether to author the verifying feature first (via feature-decompose) or to declare the mission's verifying criterion as a deferred decision and revisit.

Operations

1. Read inputs

Load and parse, in this order:

• project/goals.md — extract every O-<n> outcome ID and its one-sentence description.
• The audience artefact — extract every audience identifier and its category, interaction surface, and expectation.
• project/roadmap.md — list every roadmap item carrying mvp: true (or note that mvp is unset across the queue, in which case operation 3 will flag the MVP scope as a fresh decision).
• project/features/ — list every feature file plus its acceptance-<n> IDs so the user has a menu when picking the verifying feature.

2. Walk SMART one letter at a time

Surface each letter to the user; never batch.

1. Specific — propose a single-sentence mission_statement that names what the project does and for whom. The "for whom" MUST resolve to one or more entries from the audience artefact's identifier list. Iterate with the user until the sentence is one sentence, no markdown beyond inline punctuation, and the audience identifier is explicit (not "for users").
2. Measurable — present the feature menu from operation 1 and ask the user to pick exactly one <feature-id>:acceptance-<n> pair. Verify the named feature file exists and the named acceptance ID exists on it. Reject any pair that doesn't resolve.
3. Achievable — present the mvp: true roadmap items (or, if none yet, walk the roadmap with the user and gather the MVP scope). Verify every selected item carries detail: fine and a non-null target_sprint per the sibling roadmap spec. The MVP count SHOULD be roughly two-to-five sprints' worth of capacity; reject an unbounded scope (every roadmap item flagged) with the verbatim error from the spec.
4. Relevant — ask which outcome IDs the mission ties to. Reject an empty list and any unresolved entry. Prefer one or two; long lists are a smell.
5. Time-bound — offer the two legal shapes: { kind: outcome, ref: O-<n> } or { kind: mvp_completion }. Reject any free-text deadline or calendar date with the spec's verbatim rejection.

3. Walk audiences one at a time

For every audience identifier on the audiences list, gather a three-to-five-sentence paragraph naming the audience and stating what the MVP delivers to that audience specifically. Group two audiences in a single paragraph only when their MVP-deliverable is genuinely identical and the grouping rationale is stated in the paragraph. A bare audience list without per-audience paragraphs MUST be refused.

4. Compose the file

Render the mission file with:

• YAML frontmatter carrying the eight required fields in the declared order: mission_statement, relevant_outcomes, audiences, verifies_via, time_bound, mvp_status, created, revised_at. Set mvp_status: defining, created to today's ISO date, revised_at: null.
• ## Statement — repeat the mission_statement as prose, immediately followed by a five-line SMART decomposition naming which frontmatter field anchors each letter.
• ## Audiences — one paragraph per audience identifier, in the same order as audiences. No paragraph names an audience absent from the frontmatter list, and no frontmatter audience lacks a paragraph.
• ## Verification — short prose pointer to the verifies_via feature plus the criterion text repeated verbatim from the feature file so the mission is readable without walking the feature corpus.
• ## Source — the audit trail: the audience artefact path plus its last-commit SHA at write time (git log -n 1 --format=%H -- <path>), the consulted goals.md path, and "operator: via mission-define skill, commit-pending".

5. Confirm and write

Present the full draft (frontmatter plus body) back to the user in their language and iterate until they approve. Only then write project/mission.md. Never write a partial file; either every required field and section is present or the write is deferred.

After writing, remind the user that the next mission-side operation is mission-revise (for the defining → in_progress flip once the first MVP item enters status: active) and that mvp: true flags on roadmap items are the authoritative MVP-membership signal — keep them in sync via roadmap-plan, never inline-edit them from this skill.

Gotchas

• The Time-bound letter does not map to a date even when the user volunteers one. The two legal shapes are outcome-anchored or mvp_completion-anchored; reject calendar dates with the spec's verbatim rejection rather than translating them into a fake mvp_completion.
• The verifies_via field names exactly one feature plus exactly one acceptance-<n> ID. The sibling feature spec already enforces "at most one feature per sprint carries a non-null verifies_sprint_value"; if the user proposes two verifying features, the mission scope is wrong, not the constraint.
• The audience artefact path is not always AUDIENCES.md — it's whatever the project's audience-identification run picked (README section, dedicated file, or ADR). Read the actual artefact and capture its real path plus last-commit SHA in ## Source; never hard-code AUDIENCES.md.
• An mvp: true flag on a roadmap item without detail: fine and a non-null target_sprint is a roadmap-side lint violation, not something to silently accept here. Surface it back to the user and ask whether to fix the roadmap first via roadmap-plan (which owns the MVP flag, the detail promotion, and the sprint retarget).
• The ## Source audit trail is part of the spec contract, not optional metadata. A first-write without an audience-artefact SHA, a goals.md reference, and an authorship line fails validation downstream.

Examples

• Read examples/01-fresh-mission-claude-plugin.md when writing a first project/mission.md for a Claude plugin project.
• Read examples/02-mission-with-multiple-audiences.md when the project has multiple distinct audiences that each need a dedicated outcome.
• Read examples/03-refusal-when-mission-exists.md when the user triggers define but a project/mission.md already exists on disk.

Resumability

Per spec/claude/resumable-work/, this skill is resumable: true. State is persisted to .resume/mission-define/<run-id>.yml after every successful user-approval gate and after each named phase boundary. On re-invocation, scan that directory for files with status: in_progress whose inputs: snapshot matches the current invocation; if one matches, prompt the operator with Resume run <run_id> from phase <phase> (last checkpoint <last_checkpoint_at>)? [resume / start-new / discard]. The state-file envelope (schema_version, run_id, inputs, phase, decisions[], status, ...) and the fail-closed semantics on schema or YAML errors are load-bearing in the spec; don't duplicate those rules here.

Hard rules

• Never create project/mission.md when one already exists. First-write only.
• Never invent audience identifiers, outcome IDs, or feature-acceptance pairs. Every reference MUST resolve to an existing artefact at write time.
• Never accept a calendar date or free-text deadline in time_bound. The spec's two legal shapes are the only legal shapes.
• Never accept an MVP scope that flags every roadmap item with mvp: true. The Achievable bound exists for a reason.
• Never set mvp_status to anything other than defining on first-write. Lifecycle transitions are mission-revise's job.
• Never name an audience in ## Audiences that's absent from the audiences frontmatter, or vice versa. The two surfaces are bidirectionally validated.
• Never batch the SMART walk or the audience walk. Per-step user confirmation is the contract.
• Never copy an existing mission file from another repository. Each project's mission is its own.
• When spec/project/mission/ disagrees with this skill, the spec wins. Propose updating this skill rather than silently diverging.