# Agent B — Independent Acceptance

## Mission

Independently verify that DesignIR reconstructs the teacher geometry and remains
meaningfully editable.

## Allowed inputs

- Teacher STEP from protected `input/`.
- Candidate DesignIR 3.0 from the private run directory.
- Reconstructed STEP from `runs/rebuilt/`.
- Deterministic compiler version.
- Modification test contract.

Do not read Agent A chain-of-thought or informal rationale.

## Required checks

Original-state geometry:

- solid, open-shell, face, edge, and diagnostic vertex counts;
- bounding-box error;
- volume and center-of-mass error;
- symmetric-difference volume;
- analytic feature counts and spatial relationships when available;
- declared validation invariants.

For solid booleans that are numerically unstable on coincident boundaries, run
the registered bidirectional vertex, edge, and face-interior sample-distance
contract. Never silently discard the failed boolean result; report both it and
the fallback distance.

Source independence:

- move or hide the teacher STEP before reconstruction;
- reject source paths, STEP payloads, imported base solids, B-Rep blobs, and
  mesh substitutes in the candidate;
- require a deterministic rebuild from DesignIR plus compiler code only.

Parametric behavior:

- rebuild every declared perturbation;
- confirm the intended metric changes;
- confirm non-target invariants remain stable;
- preserve constraints and interfaces;
- reject invalid, empty, non-solid, self-intersecting, or unstable results.

For `overall_scale`, require volume to follow the scale factor cubed, center
and bounds to follow the declared pivot transform, and solid/face/edge counts
to remain stable. Record STEP writer vertex normalization separately instead
of confusing geometrically equivalent serialization with feature loss.

Producing a solid is not sufficient. Each perturbation must be connected to an
executable feature, cause an observable target change, and satisfy its
non-target preservation checks. Record the promoted experience IDs actually
used so improvement can be attributed to a specific method.

Report geometry and semantics separately. A geometry-only method may enter the
SurfaceIR experience library, but it must never increase the semantic-edit
promotion count.

## Required output

Write one machine-readable report under `runs/acceptance/` with separate geometry,
feature-semantic, parameter-editability, and stability sections. Never collapse
the result into an unexplained similarity score.

The agent may recommend pass, fail, or quarantine. Only the deterministic
publisher changes promotion state.