Slop Eval
Evaluate a design the way skill-evaluation evaluates a skill: every finding
cites concrete evidence, every axis gets a 0–100 score, arithmetic runs
through a script, and the output is a structured report — never a vibe check.
The tell catalog lives in references/tells.md; read it before sweeping.
The positive rubric (signature formula, cohesion checks, slop→premium pairs,
and the "Adding Soul" guide) lives in references/premium-markers.md; read
it before scoring Axes 7–8 and when writing fix prescriptions.
The design context guide lives in references/contexts.md; read it to adjust
priorities and tolerances based on the type of design being evaluated.
Source
- The pols.dev anti-slop design law — the tell catalog, absolute rules, and signature formula are distilled from it.
- Method modeled on skill-evaluation (cite-or-cut, weighted axes, scripted scoring, failure-mode diagnosis).
Parameters
| Parameter | Description | Default |
|---|---|---|
target |
What to evaluate: live URL, screenshot(s), code path, or Figma export | Ask user |
brief |
Brand brief or explicit user directions the design followed | None |
context |
Design type: landing, saas, editorial, ecommerce, or auto |
auto |
output |
Path to write the report | ./SLOP-REPORT.md |
compare |
Path to a previous report for tracking mode (temporal evolution) | None |
Write the report in the language the user is speaking; keep tell IDs and names in English so they stay greppable against the catalog.
Evaluation modes
Standard mode (default)
Single evaluation of a design. Produces a Slop Report with scores, tells, section ledger, and prioritized fixes.
Comparison mode
Side-by-side evaluation of two different designs (e.g., competitor analysis,
A/B variants). Add --compare pointing to another target or existing report.
Tracking mode
Evaluate the same design over time to measure improvement. Use when:
- Running weekly/sprint design reviews
- Measuring progress after a redesign
- Validating that fixes actually moved the score
Usage:
# First evaluation — establishes baseline
slop-eval --target https://site.com --output ./reports/baseline.md
# Later evaluation — tracks evolution
slop-eval --target https://site.com --output ./reports/week-2.md \
--compare ./reports/baseline.md
Tracking mode adds to the report:
- Score progression table with trends (✅ improved / ⚠️ regressed)
- Tells resolved (what got fixed)
- New tells (what got introduced)
- Regressions (axes/sections that got worse)
- Section ledger evolution
- Velocity metrics (tells resolved per week, score improvement rate)
- Recommendations for next iteration
See references/output-template.md for the full tracking output format.
Evidence channels
What you can verify depends on what you were given. Never score a check you could not observe — mark it Unverifiable and exclude it (like N/A in skill-evaluation).
| Channel | Can verify | Cannot verify |
|---|---|---|
| Code (CSS/JSX/HTML) | Fonts, hex values, gradients, shadows, radii, opacity:0 gating, icon imports, layout skeletons |
Optical centering, rendered contrast, seams, whether controls respond |
| Screenshot(s) | Everything visual: palette, type, layout, alignment, centering, clipping, contrast, seams | Hover/scroll motion, dead controls, invisible-content trap, responsive behavior |
| Live URL (browse + screenshot) | All of the above plus interactions, motion, fold ownership | Only what you didn't exercise |
With code, grep before you stare: fonts.googleapis|next/font,
lucide-react, linear-gradient, box-shadow, border-radius: *9999,
backdrop-filter, opacity: *0, initial={{ *opacity: *0,
overflow: *hidden, clip-path, position: *fixed. Each hit is a lead,
not a verdict — confirm against the catalog entry before recording it.
Evidence acquisition SOP
Route by what the target is; always end with an evidence inventory
(what was captured, what is Unverifiable) — it feeds the report header.
Live URL — the richest channel; prefer it whenever reachable.
Use whatever browser automation this session has (a browser MCP such as
Playwright or Chrome DevTools, or npx playwright screenshot as the
no-MCP fallback) and capture, saving every artifact to the scratchpad so
findings can cite file + region:
- Load at desktop (1440×900) and mobile (390×844); wait for network idle.
- Full-page screenshot of both viewports immediately after load,
before any scrolling — sections sitting at
opacity:0waiting for a scroll reveal show up blank here (M1 evidence). - Scroll pass top to bottom, then a second full-page capture; diff the two mentally for reveal-gated content, seams (C11, X13), and fold ownership (L16).
- Interaction pass: hover the primary CTA, one card, one nav link (M2–M4); click every tab, accordion, toggle, and button (M8); Tab through the page and confirm a visible focus ring (X14).
- Zoom crops at 2x of: anything near a clipped edge (X2), circled/tiled numbers and icons (X1), pricing columns side by side (X3), button labels (X5).
- Pull the rendered sources for the code-channel greps: font names from
the network panel or
<link>/@font-face, computed hex values from the stylesheets.
No browser automation available → fetch the HTML/CSS (curl) and run the
code channel on it, ask the user for full-page desktop + mobile prints,
and mark every visual-only and interaction check Unverifiable until the
prints arrive. Never score a visual check from raw HTML.
Screenshots — Read each image. If only partial crops were provided, ask for full-page desktop + mobile before sweeping (a hero-only print cannot support L11, L15, or the cohesion axis). All interaction checks (M1, M8, X14, hover tells) are Unverifiable.
Code path — run the greps, read every file they hit, plus the layout/ page components and global styles. If the project runs locally, start its dev server and continue under the Live URL SOP — code plus a live render is the only combination that can verify everything.
Figma export — treat as Screenshots for visual tells; additionally
fonts, hex values, and spacing are exact from the file. Motion and
interaction axes are Unverifiable (score NA for Axis 5 unless
prototypes were shared).
Axes and weights
| # | Axis | Weight | Scored from |
|---|---|---|---|
| 1 | Color & Light | 2x | Tells C1–C15 |
| 2 | Typography & Copy | 2x | Tells T1–T10, W1–W3 |
| 3 | Components & Ornament | 1x | Tells K1–K27 |
| 4 | Layout & Composition | 2x | Tells L1–L21 |
| 5 | Motion & Interaction | 1x | Tells M1–M8 |
| 6 | Execution & Craft | 2x | Tells X1–X14 |
| 7 | Signature & Uniqueness | 3x | 7-element formula (positive rubric) |
| 8 | Cohesion | 2x | 4 checks (positive rubric) |
Axis 7 carries the heaviest weight on purpose: the law's deepest rule is that dodging the tell list is still slop — a page with zero tells and no signature is unfinished work wearing restraint as an alibi.
Scoring
Axes 1–6 (tell-counted). Count confirmed tells on the axis by severity,
then: score = max(0, 100 − 30·critical − 15·major − 5·minor). Run
scripts/score.py axis CRIT MAJOR MINOR — don't do it by hand. One tell,
one count: a pattern repeated across sections is still one tell (note the
repetition in the evidence; repetition may upgrade minor → major where the
catalog says so).
Axis 7 (Signature). Score each of the 7 formula elements 0 (absent),
50 (attempted, weak), or 100 (strong) per the rubric in
premium-markers.md; the axis is their mean.
Axis 8 (Cohesion). Same 0/50/100 on the 4 cohesion checks; mean.
Compounding rule. Three or more major layout tells on one page cap Axis 4 at 40 — a page assembled from known skeletons is slop no matter how clean each block is.
Gates (pass as --cap to the overall run):
- Signature gate: Axis 7 < 40 caps the overall at 59 (grade C max). No amount of clean spacing rescues a page with no signature.
- Absolute-rule gate: any confirmed critical tell caps the overall at 69 (no grade A with broken execution).
Overall & Slop Index.
overall = sum(axis_score × weight) / sum(weight) # capped by gates
Slop Index = 100 − overall
Run scripts/score.py overall 1:80:2 2:65:2 ... [--cap 59] [--cap 69].
Unverifiable axes score NA and drop out of both sums. --fail-below N
exits non-zero for CI gating, e.g. gating a PR on its preview deploy:
# .github/workflows/slop-gate.yml (step excerpt)
- name: Slop gate
run: |
# run slop-eval against $PREVIEW_URL, export each axis score, then:
python3 skills/slop-eval/scripts/score.py overall \
1:$A1:2 2:$A2:2 3:$A3:1 4:$A4:2 5:$A5:1 6:$A6:2 7:$A7:3 8:$A8:2 \
--fail-below 40
Grade scale
| Grade | Overall | Slop Index | Verdict |
|---|---|---|---|
| A | 80–100 | 0–20 | Premium — deliberate, signed, executed |
| B | 60–79 | 21–40 | Considered — mostly deliberate, some defaults |
| C | 40–59 | 41–60 | Generic — clean but templated or unsigned |
| D | 20–39 | 61–80 | Slop — assembled from presets |
| F | 0–19 | 81–100 | Pure slop |
Absolute rules check
Six execution laws, each pass/fail/unverifiable, reported in their own table. Any fail is a critical tell (counts on its axis AND triggers the absolute-rule gate):
- Content visible by default — nothing gated on an entrance animation
(
opacity:0+ reveal) (M1) - Clear the cut — no text/control sliced by clip, notch, overflow, or fixed height (X2, X11)
- Parallel alignment — comparable columns share baselines; buttons anchored (X3)
- Real centering — everything meant to be centered is, mathematically and optically (X1)
- Legible contrast — every text clears its background by a real value gap (X5)
- Controls work — every interactive-looking control responds (M8)
Workflow
- Gather evidence — route the
targetthrough the Evidence acquisition SOP above. Done when the evidence inventory states what was captured and what is Unverifiable. - Read
references/tells.md— the catalog you sweep against. - Sweep axes 1–6 — walk the catalog group by group. Cite-or-cut:
a tell is only recorded with concrete evidence (hex value, font name,
file:line, or screenshot region); no evidence, no tell. Check each candidate against its premium-pair note — the crafted version of a pattern is not the tell. Done when every catalog group has been swept and every recorded tell carries a citation. - Run the absolute rules check — all six, pass/fail/unverifiable with evidence.
- Score Axes 7–8 — read
references/premium-markers.md, score the 7 signature elements and 4 cohesion checks with one-line justifications each. Done when all 11 items carry a score and a justification. - Compute —
score.py axisper tell-counted axis, thenscore.py overallwith weights and any triggered--cap. Never hand-compute. - Write the report — read
references/output-template.mdand emit exactly that structure tooutput, ending with the 3–5 prioritized fixes that would move the score most (biggest weighted deltas first; a missing signature usually outranks any single tell).
Gotchas
- The brief overrides the law. If the user or brand explicitly directed a choice (a color, a layout, an effect), it is not a tell — the law itself says the user's word wins 100%. Ask for the brief when the design clearly follows one; note excluded tells in the report with proper justification tags (see Exclusion system below).
- Context flips a tell. Mono on real data is correct; a populated, real-feeling product window is a signature, not the fake-window tell; a tight micro-grid with texture is premium, a full-page graph paper is slop. Always check the premium pair before recording.
- Don't reward the clean miss. Zero tells with a weak signature is the most common failure of designs that tried to avoid slop. The signature gate exists for this — apply it without mercy.
- Severity discipline. Critical is reserved for broken (the six absolute rules). A blue-purple gradient is loud but not broken: major.
- One-axis bleed. Some tells could sit on two axes (cut-off glow is color and execution). The catalog assigns each tell to exactly one axis — count it only there.
- Portfolio tells. L19 (recycling your own house style) needs prior work from the same author to verify; without it, mark Unverifiable rather than guessing.
Exclusion system
Every excluded tell MUST have a justification tag. A tell without a tag counts — no exceptions. This creates an audit trail and prevents lazy exclusions.
Justification tags
| Tag | When to use | Example |
|---|---|---|
// BRIEF: |
Client/stakeholder explicitly directed this choice | // BRIEF: client requested blue-purple gradient as brand identity |
// DESIGN DECISION: |
Documented design decision with concrete reasoning | // DESIGN DECISION: countdown is real — sale ends 2026-08-01 |
// CONTEXT: |
Design context makes this pattern acceptable | // CONTEXT: mono typeface is appropriate for code snippets in SaaS docs |
// PREMIUM PAIR: |
This is the crafted version, not the slop version | // PREMIUM PAIR: glass effect has proper refraction, edge dispersion, tuned shadows |
Valid vs invalid exclusions
Valid exclusions:
| C1 | Blue→purple gradient | `// BRIEF: brand guidelines v2.3 specify #6366f1→#8b5cf6` |
| K14 | Countdown timer | `// DESIGN DECISION: real sale ends 2026-12-31, verified in CMS` |
| T4 | Mono as house voice | `// CONTEXT: SaaS product with code-heavy documentation` |
| K25 | Glass effect | `// PREMIUM PAIR: proper backdrop blur, chromatic dispersion, directional light` |
Invalid exclusions (tell still counts):
| C1 | Blue→purple gradient | "we liked it" | ❌ Not a justification
| K9 | Default CTA pair | "it's our style" | ❌ Too vague
| L1 | Default hero stack | "approved by team" | ❌ Who? When? Why?
| K6 | Kitchen-sink card | "industry standard" | ❌ Slop IS the industry standard
Exclusion limits
- >5 exclusions → Review each one. Mass exclusions suggest the brief wasn't followed or the evaluator is being too lenient.
- >10 exclusions → Something is wrong. Either the brief allows nearly everything (in which case, why evaluate?) or exclusions are being used to inflate the score.
- Excluding signature elements → Almost never valid. If S1–S7 are excluded, the design has no signature by definition.
Exclusion documentation in report
In the Excluded tells table, format as:
## Excluded tells
| ID | Tell | Exclusion reason |
|----|------|------------------|
| C1 | Blue→purple gradient | `// BRIEF: brand guidelines v2.3 specify #6366f1→#8b5cf6` |
| K14 | Countdown timer | `// DESIGN DECISION: real sale ends 2026-12-31, verified in CMS` |
**Exclusion summary:** 2 tells excluded (1 BRIEF, 1 DESIGN DECISION)
Challenging exclusions
When reviewing someone else's slop report, check exclusions first:
- Is the tag present? No tag = tell counts.
- Is the tag appropriate?
// BRIEF:needs an actual brief reference. - Is the reasoning concrete? Vague reasoning = tell counts.
- Is the exclusion count reasonable? >5 warrants scrutiny.
Quality checklist
Final gate before delivering. Run through every item — a single failure means the report is not ready. This is the self-evaluation rubric; treat it as a hard gate, not a suggestion.
Pre-sweep checks
- Evidence inventory complete — documented what was captured (code, screenshots, live URL) and what is Unverifiable
- Brief documented — if provided, summarized in report header; if not provided, noted as "no brief"
- Design context identified — what type of design is this? (landing
page, SaaS dashboard, editorial, e-commerce). Read
references/contexts.mdto adjust priorities and tolerances - All reference files read —
tells.md,premium-markers.md, andcontexts.mdloaded before starting the sweep
During-sweep checks
- Cite-or-cut enforced — every recorded tell has ID + severity +
concrete citation (hex value, font name,
file:line, or screenshot region) - Premium pair checked — before recording any tell, verified it's not the crafted premium version of the pattern
- Portability test applied — for borderline cases, asked: "Could this element be moved to another site without alteration?" If yes → tell. If no (it's specific to this brand) → not a tell
- Defense test applied — for borderline cases, asked: "Could the designer defend this choice with concrete reasoning if asked?" If no → tell. Slop cannot be defended; deliberate choices can.
- Section attribution — every tell assigned to a specific section (Hero, Features, Pricing, Footer, etc.) for the Section Ledger
- Severity discipline — critical reserved for absolute-rule violations only; no severity inflation
Exclusion checks
- Exclusions documented — every excluded tell has a
// BRIEF:or// DESIGN DECISION:justification - Exclusions are genuine — "we liked it" or "it looked good" are NOT valid exclusion reasons. Only explicit brief direction or documented design decisions with concrete reasoning qualify.
- Exclusion count reasonable — if >5 tells excluded, double-check each one. Mass exclusions suggest the brief wasn't followed, not that the tells don't apply.
Post-sweep checks
- All unverifiable checks marked — not silently passed or skipped
- All 6 absolute rules reported — pass/fail/unverifiable with evidence
- All 11 signature/cohesion items scored — 0/50/100 with one-line justification each
- Section Ledger complete — every major section has a verdict (CLEAN/SUSPICIOUS/INFLATED/CRITICAL) with tell count and action
- Gates applied correctly:
- Signature gate: if Axis 7 < 40, overall capped at 59
- Absolute-rule gate: if any crit, overall capped at 69
- Compounding cap: if ≥3 major layout tells, Axis 4 capped at 40
- Math from script only — all scoring via
score.py, never hand-computed
Report checks
- Template followed exactly — structure matches
output-template.md - Fixes ranked by weighted impact — signature issues (3x weight) typically outrank single tells
- Language correct — report in user's language, tell IDs in English
Final self-audit
Before delivering, ask yourself:
- "What still looks like obvious slop that I didn't flag?" — if something visually screams slop but isn't in your findings, either find the tell that covers it or note it as a gap in the catalog.
- "Did I over-correct?" — a sparse report on a clearly-slop design suggests missed tells. A bloated report on a premium design suggests false positives.
- "Would I trust this report if someone else wrote it?" — read the report as if reviewing a colleague's work. Does every claim hold up?