Measuring file sizes and formats requires Bash

This skill's report asks for file sizes against budgets, texture dimensions (power-of-two), audio sample rates, and last-modified times for orphan detection. None of those are obtainable from Read/Glob/Grep — they need stat or a binary header read, so the read-only measuring commands (stat, file, od, wc, du) are pre-approved above; list files with Glob. Anything else asks first.

If you cannot take a measurement, the cell is NOT ASSESSED, never an estimate. A size budget table filled from guesses is worse than an empty one: it looks like evidence. This is a live fabrication vector even on a project full of real assets: if the template demands tables of numbers the tool allowlist cannot produce, the only way to complete it is to invent them.

Insufficient input — check this before producing any report

If the inputs this skill needs do not exist, the answer is "could not run" — not a filled-in report. Check first, and stop if the check fails.

1. List the inputs this skill reads (data files, prior reports, profiler output, test results, registries, source code).
2. For each, record FOUND or ABSENT — not "assumed present".
3. If any input required for a section is ABSENT, that section is NOT ASSESSED — NO DATA. Do not estimate it, do not infer it from an adjacent artifact, and do not leave a mandated cell to be filled by whoever reads the template next.
4. If every required input is ABSENT, stop and report NOT ASSESSED — NO DATA as the whole verdict, naming what was missing and which skill produces it.

A verdict of NOT ASSESSED is a success. It is the correct, useful answer to "what does the data say?" when there is no data. The failure mode this prevents is specific and has been observed in practice: report templates whose verdict enum had no "could not run" state produced false clean passes — an asset audit returning COMPLIANT on a project with no assets and no standards, and a performance profile reporting ">99% headroom against a 16.67ms budget" with zero profiler data and no budget ever set.

Absence of evidence is never evidence of absence. A scan that finds no matches because there are no files to scan has not verified anything. Say which of the two happened — a reader cannot tell from a green result.

Phase 1: Read Standards

Read the art bible's Asset Standards section (design/art/art-bible.md) and any asset standards in the relevant design docs — size budgets and format rules come from there. The naming patterns are the ones in Phase 3 below, unless the art bible states its own.

If neither states a size budget — or there is no art bible — the Size section is NOT ASSESSED — no size budget set, and the report names /art-bible, whose Asset Standards section sets budgets, formats and the naming convention.

Phase 2: Scan Asset Directories

Assets live under the engine's asset root: assets/ on Godot, Assets/ on Unity, Content/ on Unreal. Resolve the engine and its code root per .claude/docs/code-root-resolution.md; that code root is the one Phase 3's orphan and missing-asset searches read. If it is unresolved, stop: NOT ASSESSED — engine unresolved, naming /setup-engine.

Scan the asset root using Glob:

• Godot — assets/art/**/*, assets/audio/**/*, assets/vfx/**/*, assets/shaders/**/*, assets/data/**/*
• Unity — Assets/**/*, leaving out scripts (*.cs, *.asmdef) and *.meta files
• Unreal — Content/**/*.uasset and Content/**/*.umap

The files matched are Total assets scanned. If there are none, the checks on scanned files — Naming, Size, Format, Orphaned — are NOT ASSESSED — no assets under <asset root>; the missing-asset search still runs.

Phase 3: Run Compliance Checks

Naming conventions:

• Art: [category]_[name]_[variant]_[size].[ext]
• Audio: [category]_[context]_[name]_[variant].[ext]
• All files must be lowercase with underscores

These are Godot's conventions. Unity and Unreal name assets in PascalCase, so on those engines check names only against a naming rule the art bible states; with none, Naming is NOT ASSESSED — no naming rule for <engine> (name /art-bible).

File standards:

• Textures: Power-of-two dimensions, correct format (PNG for UI, compressed for 3D), within size budget
• Audio: Correct sample rate, format (OGG for SFX, OGG/MP3 for music), within duration limits. file reports an audio file's format and sample rate but not its length, and no pre-approved tool here does; a duration budget is therefore NOT ASSESSED — duration not measurable here, naming the files it covers.
• Data: Valid JSON/YAML, schema-compliant

On Unreal an asset file (.uasset, .umap) does not keep its source file's format or dimensions, so Format is NOT ASSESSED there; its size is still measured.

Orphaned assets: Search the code root for references to each asset file. Flag any with no references.

Missing assets: Search the code root for asset references and verify the files exist.

Both searches need code: if the code root holds no source files, Orphaned and Missing are NOT ASSESSED — no code to search. On Unity and Unreal most asset references live in scenes, prefabs and other assets rather than code, so an asset no code names may still be in use: Orphaned is NOT ASSESSED there.

Phase 4: Output Audit Report

# Asset Audit Report -- [Category] -- [Date]

## Summary
- **Total assets scanned**: [N]
- **Naming violations**: [N]
- **Size violations**: [N]
- **Format violations**: [N]
- **Orphaned assets**: [N]
- **Missing assets**: [N]
- **Sections not assessed**: [none | each section and why]

## Naming Violations
| File | Expected Pattern | Issue |
|------|-----------------|-------|

## Size Violations
| File | Budget | Actual | Overage |
|------|--------|--------|---------|

## Format Violations
| File | Expected Format | Actual Format |
|------|----------------|---------------|

## Orphaned Assets (no code references found)
| File | Last Modified | Size | Recommendation |
|------|-------------|------|---------------|

## Missing Assets (referenced but not found)
| Reference Location | Expected Path |
|-------------------|---------------|

## Recommendations
[Prioritized list of fixes, one per violation, each naming the change — the
target resolution or compression for a size violation, the corrected name for a
naming violation, the target format for a format violation]

## Verdict: [NOT ASSESSED / COMPLIANT / WARNINGS / NON-COMPLIANT]

Choose the verdict by the findings, first match wins:

• NON-COMPLIANT — any size violation, or any asset that code references but that does not exist
• WARNINGS — only naming, format or orphaned-asset findings
• NOT ASSESSED — the audit did not cover its scope: no data at all (the path above), zero assets scanned, or any section NOT ASSESSED — name which. It ranks below the two finding verdicts, because a measured violation is more actionable than a gap, and above COMPLIANT
• COMPLIANT — at least one asset scanned, every section assessed, no findings

This skill is read-only — it produces a report but does not write files.

Phase 5: Next Steps

• Fix naming violations using the Phase 3 patterns (or the art bible's, where it states its own).
• If standards were missing, run /art-bible to write its Asset Standards section.
• Delete confirmed orphaned assets after manual review.
• Run /content-audit to cross-check asset counts against GDD-specified requirements.