Write a tracer-bullet card — a precise specification for one thin end-to-end slice of work. Use when scoping a new slice, defining what to build next, or breaking a feature into provable increments. Covers target behavior, boundary crossings, risks, and definition of done.
Write a tracer-bullet card — a precise specification for one slice of work that will be implemented with /pragma:slice.
The behavior to deliver: $ARGUMENTS
Precondition: a concept capsule must exist. If none exists, stop and recommend /pragma:capsule first. Read the capsule — the card must use glossary terms and respect invariants.
Write a card with exactly these four fields:
What should be true when this slice is done? Single declarative sentence.
Good: "A markdown file with YAML front-matter is parsed into a Post with title, date, and body." Bad: "Implement the parsing system" (too vague) / "Add support for markdown, YAML, TOML, and JSON" (too many things)
Every boundary the tracer bullet passes through:
→ [entry point] (e.g., CLI argument, HTTP request, function call)
→ [layer/boundary] (e.g., parser, domain core, adapter)
→ [exit point] (e.g., file written, response sent, value returned)
Be specific ("the PostgreSQL adapter", not "the backend"). Note boundaries that don't exist yet.
- RISK: [what might not work] → MITIGATION: [how we'll handle it]
- ASSUMPTION: [what we're assuming] → VALIDATED BY: [how we'll know]
- BUY-OR-BUILD: [buy|build + why package/tool fit is or is not acceptable]
- PROTOTYPE PLAN: [if requirement behavior is unclear, how we'll prototype and observe it]
- OUT OF SCOPE: [explicitly excluded for this slice]
/pragma:spike first, not a /pragma:slice✓ [test name] — [observable assertion checked by that test]
✓ [test name] — [observable assertion checked by that test]
/pragma:slice (red step)Cards are ephemeral — consumed by /pragma:slice, then the definition of done becomes the test.
docs/cards/ if the user wants to track themAppend to the response:
planning/pragma:slice/pragma:consult (default unless user explicitly continues directly)