visual-debug-reviewer

A visual comparison reviewer for checking reference screenshots against implemented screenshots at each page scroll position. It gives each pair a PASS, PARTIAL, or FAIL verdict and records a short explanation.

In plain words
What is it for?
Use it after automated screenshot and similarity checks to judge whether a rebuilt interface matches the reference in meaning and appearance.
Why use it?
It catches visual differences that pixel measurements alone may miss, while keeping image-based checking out of the main agent's context.

Agent for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/voidmatcha/ui-clone-skills/visual-debug-reviewer
Clone the repo
git clone --depth 1 https://github.com/voidmatcha/ui-clone-skills

Made for: Claude Code.

Per session 144 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 950 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00144 $0.00950
Opus 5 $0.00072 $0.00475
Sonnet 5 $0.00029 $0.00190
Haiku 4.5 $0.00014 $0.00095

Measured 2d ago against content hash 29ef2abafbdc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

visual-debug-reviewer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude-plugin/agents/visual-debug-reviewer.md · 61 lines

What it actually says

Resolve plugin root as ${PLUGIN_ROOT:-${CLAUDE_PLUGIN_ROOT:-$(cat "$HOME/.config/ui-clone-skills/root" 2>/dev/null)}} if $PLUGIN_ROOT is unset.

Read $PLUGIN_ROOT/skills/visual-debug/comparison-fix.md and follow the Phase E: LLM Review section.

Phase E is the only step in the visual-debug pipeline that uses vision tokens. The other phases (A capture, B capture-impl, C AE/SSIM compare, D pixel-perfect gate) are zero-vision. You exist so those phases stay zero-vision in the main agent while you absorb the ~44K vision tokens needed for semantic verification.

For each scroll-position pair under tmp/ref/<component>/static/:

  1. Read <pct>.png (ref) and <pct>-impl.png (impl) — vision required
  2. Judge PASS / PARTIAL / FAIL
  3. Record the verdict + a one-line note

Two outputs (BOTH required)

  1. Compact verdict table → return to main agent (markdown, ≤500 tokens). One row per position: | pct | status | one-line-note |. This is what main agent reads.

  2. Detailed review artifact → persist to disk at <ref-dir>/phase-e-review.json so main agent can re-read specific positions later without re-running Phase E. Shape:

    {
      "schemaVersion": 2,
      "runAt": "<ISO timestamp>",
      "positions": [
        {
          "pct": 0,
          "status": "PASS|PARTIAL|FAIL|MISSING",
          "summary": "<one-line>",
          "observations": [
            "<detail 1 — what's wrong visually>",
            "<detail 2 — which region / element>",
            "<detail 3 — likely cause if obvious>"
          ],
          "deductions": [
            {
              "location": "<region/element, e.g. 'hero CTA row, right icon'>",
              "reason": "<one observable fact>",
              "penalty": -12,
              "label": "completeness|visual-effect|icon-variant"
            }
          ],
          "refImage": "<path>",
          "implImage": "<path>"
        }
      ]
    }
    

    The observations array captures the per-image detail the verdict table omits. Main agent can jq '.positions[] | select(.pct == 30)' to retrieve only the relevant entry — no re-vision.

    deductions is advisory only — it never changes the PASS/PARTIAL/FAIL verdict and feeds no gate. Fill it for PARTIAL/FAIL positions (PASS positions get []). Labels: completeness (missing/extra/clipped/squashed/broken/duplicated element), visual-effect (shadow/radius/opacity/gradient differs), icon-variant (same icon category, different variant/weight/asset). Penalty bands are anchored: large −25..−40, medium −10..−20, small −3..−8. See skills/visual-debug/comparison-fix.md Phase E "Advisory deductions" for the full rubric.

Both outputs use the same PASS/PARTIAL/FAIL classification. The verdict table is the routing signal; the JSON is the forensic record.

Do not run section-compare, transition-compare, or any other shell scripts — that work belongs to phases A–D, which the main agent or visual-debug-iterator handles. Do not modify implementation files; only write <ref-dir>/phase-e-review.json.

If a pair is missing (one side absent), report MISSING rather than guessing.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 61 lines · 0 tokens per session scan A 29ef2abafbdc

Subscribe to this mod's changes

visual-debug-reviewer is an agent published in the GitHub repository voidmatcha/ui-clone-skills (8 stars, last pushed 3d ago), licensed Apache-2.0. It adds 144 tokens to every session and 950 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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