Conciseness

The body is terse rather than verbose, but a meaningful share of tokens is non-actionable filler: the intro restates the frontmatter persona verbatim, the '## Capabilities' section is kebab-case tags, '## Anti-Patterns' is three empty headings, and '## When to Use' is generic placeholder boilerplate. This fits 'mostly efficient but includes some unnecessary explanation or could be tightened'. Not a 4 because roughly 40% of the content (empty headings, placeholder sentence, truncated line) earns no value.

Actionability

There is no code, no schema example, no command, and no concrete instruction anywhere — the Patterns are one-line abstractions ('Creating clear, unambiguous JSON Schema for tools', 'Returning errors that help the LLM recover') and Anti-Patterns have no content at all. This matches anchor 1 ('entirely vague or abstract; no concrete code or commands; only describes rather than instructs'). Not a 2 because even a high-level hint like a named tool or format is absent.

Workflow Clarity

No multi-step process is presented — there is no sequence of steps, no design checklist, and no validation guidance for the tool-design task the skill claims to cover, matching anchor 1 ('steps missing or incoherent; no sequence'). The simple-skill exception does not apply: the body never defines even a single unambiguous action to perform.

Progressive Disclosure

The skill is a short single file with section headers (Capabilities, Patterns, Anti-Patterns, Related Skills, When to Use), so no external references are needed and basic navigation exists. However, the sections are hollow — Anti-Patterns is empty and When to Use is placeholder text — and the intro ends mid-sentence ('You push for explicit error hand'), fitting 'some structure but could be better organized'. Not a 4 because empty sections and the truncated line are real organization gaps, not minor ones.

Specificity

The description states no concrete actions ('You are an expert in the interface between LLMs and the outside world... The difference is almost always in the design, not the implementation.') — it is a persona/philosophy statement that only loosely names a domain, matching the 'no concrete actions' anchor; additionally, the first-person voice ('You are an expert', 'You've seen') triggers the mandatory 1-point reduction from 2 to 1. It is not merely vague like 'Helps with documents' in a way that fails to even identify a domain — 'tools', 'agents', 'hallucinate' identify the LLM-tooling space — but it never states what the skill does.

Completeness

It has only a vague 'what' (an expert stance on tool design) and no 'when' clause whatsoever — an exact match for anchor 2 ('Has a vague what and no when'). It cannot score 3 because the 'what' never enumerates capabilities, and the missing 'Use when...' guidance caps it regardless.

Trigger Term Quality

A few generic domain keywords appear ('LLMs', 'tools', 'agents', 'hallucinate', 'loop') but the natural phrases a user would actually say — 'tool schema', 'function calling', 'MCP', 'tool description', 'agent tools' — are missing, matching 'one or two generic keywords; missing the natural phrases users say'. Not a 3 because the keyword set is persona language rather than the actionable trigger vocabulary users employ.

Distinctiveness Conflict Risk

The niche (LLM/agent tool design, hallucination and silent-failure causes) is somewhat specific, but without trigger phrases it could overlap with adjacent skills like api-design, backend, or debugging skills, matching anchor 3. Not a 4 because the abstract framing ('interface between LLMs and the outside world') leaves the boundary with related skills unclear.