Skill Scorer — 0-100 Rating for Any SKILL.md

Calibrated against Anthropic's own skill-creator guidelines and the patterns of 50k+ star repos (Superpowers, Caveman, mattpocock/skills). Average skill scores 45-55. If yours scores 80+, ship it.

Dependencies

None. Standalone. Reads any SKILL.md content.

CRITICAL: Auto-start

SKILL.md content in the message or just created in conversation → skip to Step 2. No preamble.

Step 1. Get the skill

Content in context? Use it. Otherwise:

Paste your SKILL.md or tell me which skill to score.

If the user names a skill in the current environment, read it.

Step 2. Score 10 Dimensions (each 0-10)

Be precise. 6.5 is 6.5, not 7. Every score needs one sentence of evidence referencing the actual skill content.

D1: Trigger Precision (0-10)

Will it fire when it should? Will it stay quiet when it shouldn't?

Evaluate the YAML description field:

• Specific trigger phrases listed? (+2)
• Natural language variations covered? (+2)
• "Pushy" quality per Anthropic guidance? (+2)
• Edge-case triggers (bare paste, implicit intent)? (+2)
• False positive risk controlled? (+2)

D2: Instruction Clarity (0-10)

Can Claude follow this without improvising?

• Unambiguous step sequence? (+2)
• Decision points with explicit branches? (+2)
• Deterministic enough that two instances produce similar output? (+3)
• No contradictory instructions? (+1.5)
• Clear scope boundaries (what it does AND doesn't do)? (+1.5)

D3: Output Predictability (0-10)

Does the user know what they'll get?

• Output format explicitly defined? (+3)
• Templates or examples provided? (+3)
• Length/scope appropriate and specified? (+2)
• Structured data output (JSON, table) available? (+2)

D4: Edge Case Coverage (0-10)

What happens with weird input?

• Empty/missing input handled? (+2)
• Extremely long input addressed? (+2)
• Invalid/unexpected input types? (+2)
• Multi-language or mixed input? (+2)
• Graceful degradation path? (+2)

D5: Anti-Hallucination Guardrails (0-10)

Does it prevent Claude from fabricating?

• Explicit "don't fabricate" rules? (+2.5)
• "If unsure, say so" instruction? (+2.5)
• Failure modes section (what skill does NOT do)? (+2.5)
• Separation of known vs. needs-verification? (+2.5)

D6: Developer Experience (0-10)

Is it pleasant to use?

• Engaging interaction style? (+2.5)
• Personality without being annoying? (+2.5)
• Appropriate for target audience? (+2.5)
• Memorable enough to recommend? (+2.5)

D7: Composability (0-10)

Does it play well with other tools?

• Output format consumable by other skills/tools? (+3)
• Explicit handoff points? (+3)
• Modular (not monolithic)? (+2)
• Avoids duplicating existing skills? (+2)

D8: Open-Source Readiness (0-10)

Would a stranger install this from a README?

• Self-contained (no private dependencies)? (+2)
• Documented well enough for strangers? (+2)
• Solves a real, recognized problem? (+2)
• Clear naming and discoverability? (+2)
• Cross-agent compatibility mentioned? (+2)

D9: Wow Factor (0-10)

Does it make people go "oh damn"?

• Novel approach or angle? (+3)
• Demo-able in 30 seconds? (+3)
• Would someone tweet/share this? (+2)
• Solves a problem in a way no one else has? (+2)

D10: Real-World Utility (0-10)

Would someone use this weekly?

• Solves a recurring problem? (+3)
• Problem is painful enough people seek solutions? (+3)
• Faster/better than manual alternative? (+2)
• Would someone miss it if removed? (+2)

Step 3. Calculate Composite Score

Formula

RAW = (D1 × 1.2) + (D2 × 1.2) + (D3 × 1.0) + (D4 × 0.8) +
      (D5 × 1.0) + (D6 × 1.0) + (D7 × 0.6) + (D8 × 1.0) +
      (D9 × 1.2) + (D10 × 1.0)

SCORE = RAW  // max possible = 100

Weight rationale: Trigger precision (D1) and wow factor (D9) weighted highest — a skill that never fires or that nobody cares about is dead on arrival. Composability (D7) weighted lowest — standalone value matters more for v1.

Verdict

Calibration Anchors

• Anthropic's docx skill = ~72 (solid execution, low wow factor)
• Superpowers = ~88 (methodology is the product, cross-agent, massive adoption)
• Caveman = ~85 (extreme wow, simple concept, measurable benchmark)
• A typical first-draft skill = ~35-45

These are reference points, not dogma. Score based on the rubric, not by anchoring to these numbers.

Step 4. Output Format

## 🎯 SKILL SCORE: [Name]

| Dim | Dimension | Score | Evidence |
|-----|-----------|-------|----------|
| D1 | Trigger Precision | X/10 | [one line referencing the skill] |
| D2 | Instruction Clarity | X/10 | ... |
| D3 | Output Predictability | X/10 | ... |
| D4 | Edge Case Coverage | X/10 | ... |
| D5 | Anti-Hallucination | X/10 | ... |
| D6 | Developer Experience | X/10 | ... |
| D7 | Composability | X/10 | ... |
| D8 | Open-Source Readiness | X/10 | ... |
| D9 | Wow Factor | X/10 | ... |
| D10 | Real-World Utility | X/10 | ... |

## COMPOSITE: XX/100 — [VERDICT EMOJI] [VERDICT]

### 🔥 Top 3 Strengths
1. [Specific, with evidence]
2. ...
3. ...

### 💀 Top 3 Weaknesses
1. [Specific, with actionable fix]
2. ...
3. ...

### 🛠️ Priority Fixes
1. [Highest-impact change — specific enough to implement now]
2. [Second]
3. [Third]

Structured Output

Always append after the narrative:

{
  "skill_score": {
    "version": "2.0",
    "skill_name": "...",
    "dimensions": {
      "trigger_precision": 0.0,
      "instruction_clarity": 0.0,
      "output_predictability": 0.0,
      "edge_case_coverage": 0.0,
      "anti_hallucination": 0.0,
      "developer_experience": 0.0,
      "composability": 0.0,
      "open_source_readiness": 0.0,
      "wow_factor": 0.0,
      "real_world_utility": 0.0
    },
    "composite": 0,
    "verdict": "SHIP|REWORK|MAJOR_REWORK|SCRAP",
    "top_strengths": ["...", "...", "..."],
    "top_weaknesses": ["...", "...", "..."],
    "priority_fixes": ["...", "...", "..."]
  }
}

Step 5. Interactive Options

What next?
A) Rewrite the weakest dimension
B) Optimize the trigger description (rewrite YAML)
C) Generate a README.md from this skill
D) Compare against another skill (side-by-side)
E) Score another skill
F) Run the Anthropic compliance check (progressive disclosure, token budget, etc.)

Step 6. Anthropic Compliance Check (option F)

When requested, run this secondary checklist against Anthropic's skill-creator guidelines:

Operational Rules

1. No flattery. "Great start!" is banned. Be specific or be quiet.
2. No score inflation. Average = 45-55 out of 100. Not 70.
3. Evidence required. Every score references the actual skill text.
4. Fixes must be actionable. "Improve the description" → useless. "Add these 5 trigger phrases: [list]" → useful.
5. Self-aware. This skill can score itself. Be hon