| name | build-tournament |
| description | Compete-mode for BUILT artifacts — landing page, component, small app, email template. Type /build-tournament <brief> to have isolated persona contestants each build the full artifact, a blind judge score them, and a revised champion ship. Reserve for high-stakes builds; one-shot first for routine work. |
| argument-hint | <the build brief — artifact, audience, constraints, success criteria> |
| disable-model-invocation | true |
| allowed-tools | Read, Grep, Glob, Bash, Write, Edit, Agent, Workflow, Skill |
build-tournament — isolated contestants, blind judge, revised champion
Angela Jiang's (Anthropic head of product) compete mode: N isolated sub-agents each build the
COMPLETE artifact from the same brief, a blind judge scores them against pre-declared criteria,
and the champion is revised with the judge's feedback plus grafts from the losers. The revision
round is where the quality comes from — raw contestant scores cluster within a few points.
When to invoke
- A high-stakes built artifact (landing page, dashboard screen, component, small app, branded
template) where direction AND execution are both open and picking wrong is costly.
- You are about to one-shot a client-facing or launch-critical build — stop and run this instead.
- NOT for routine builds: a bare one-shot with the playbook in context is the baseline; this
costs ~4x tokens and wall-clock, so the artifact must earn it.
Core procedure — DO NOT DEVIATE
- Lock the brief and criteria BEFORE spawning. Write the full business brief (product,
audience, CTA, constraints) and 4-6 scoring criteria with weights. Criteria declared after
seeing output is judge contamination. UI artifact → run
mobbin-ui-patterns first and put
the reference brief inside the contestant brief (founder directive 2026-07-13).
- Done when: brief + weighted rubric exist in a file contestants and judge both receive.
- Spawn 3 isolated contestants via the Workflow tool (this skill's instruction satisfies
its opt-in gate), one persona each, identical brief,
isolation: 'worktree' when they write
files, and explicit rules: complete the whole artifact, never ask for direction, never look
at sibling work. Personas — genuinely divergent lenses, not paraphrases:
- Operator — ships the most usable, conversion-mechanical version.
- Strategist — optimises for positioning, narrative, and differentiation.
- Skeptic — builds for the distrustful visitor; removes waffle, proves claims.
- Done when: three complete artifacts exist, none has seen another.
- Blind-judge. One fresh judge agent (never a contestant) receives the artifacts labeled
A/B/C with personas stripped, scores each against the rubric using the
judge skill's
evidence-ranked manner, and returns per-criterion scores + specific defects + strongest
element of each artifact.
- Done when: scored table + defect list + graft candidates exist.
- Champion revision — mandatory, the actual alpha. Take the winner, apply the judge's
defect list, graft the named strongest elements from the losers. Never blind-ship the raw
winner; never concatenate artifacts. One revision round only.
- Done when: revised champion addresses every judge defect or logs why not.
- Verify and hand back. Run the artifact (
/verify discipline — render it, drive it) and
return the tournament record. Code that ships goes through the normal merge-gate path.
- Done when: champion observed working + record emitted.
Output format
Return to the caller (and drop beside the artifact as tournament-record.md):
scores table (per criterion, per contestant), winner + rationale, defects fixed in revision,
grafts taken (from whom, what), and the champion's location.
Calibration
- 3 contestants default; 5 max only when the brief names >3 truly distinct audiences/angles.
- Contestants run at medium effort — diversity + judge + revision recover depth (same doctrine
as
output-tournament). Judge and revision run at high effort.
- Live benchmark: contestant scores 91/93/92 — a spread under ~5 points is normal and does NOT
mean the tournament failed; the revision round is the payoff.
- One revision round. A second tournament on the champion is scope creep — hand back instead.
What this skill is NOT
- Not
output-tournament — that competes short creative VARIANTS (copy, taglines, directions);
this competes complete built artifacts with file output and worktree isolation.
- Not
boardroom/ceo-board — those triangulate a decision; nothing is built.
- Not
opus-adversary — that reviews ONE existing artifact; here generation itself competes.
- Not a substitute for loops — for iterative refinement of a known direction, loop instead
(ranked above tournaments in the source's own testing).
Hard rules
- Contestants never see each other's work; the judge never sees personas. Contamination
observed to collapse the diversity the pattern depends on.
- The judge is never a contestant (builder≠reviewer — Anthropic engineer doctrine).
- Synthesis is grafting into ONE coherent artifact — concatenation is the dominant naive
failure.
- Client-facing words inside the artifact still route through
nexus-copywriter; the
tournament does not bypass the estate content gate.
- Declare rubric before generation. Post-hoc criteria let the judge rationalise a favourite.
Provenance
