Conciseness

The body is short and mostly terse, but the opening persona paragraph ('You are an expert in the interface between LLMs and the outside world... A simple tool with crystal-clear documentation will succeed') is motivational padding that adds no guidance, and it too is truncated ('You push for explicit error hand'). It does not fall to score 2 because only one section is padded and no space is spent explaining concepts Claude already knows.

Actionability

There is no code, command, or example anywhere in the body — even the highest-value content, the pattern and anti-pattern sections, is purely nominal ('Returning errors that help the LLM recover', '❌ Vague Descriptions'). This matches the score 1 anchor: it only describes rather than instructs.

Workflow Clarity

No steps or sequence of any kind are present; the body never tells Claude what to actually do when the skill is invoked (no design procedure, no review checklist, no validation of schemas). This matches the score 1 anchor of steps missing with no sequence; score 2 would require at least a rough sequence, which is absent.

Progressive Disclosure

The body is short with clear section headers (Capabilities, Patterns, Anti-Patterns, Related Skills) and no nested references, but the three Anti-Pattern headers ('❌ Vague Descriptions', '❌ Silent Failures', '❌ Too Many Tools') are completely empty, and no bundle files exist to carry the example material this topic needs. It does not reach score 4 because empty sections and missing example content leave the organization incomplete rather than just minor-gapped.

Specificity

The description enumerates specific topics ('JSON Schema best practices, description writing that actually helps the LLM, validation, and the emerging MCP standard') but frames them as subject areas rather than concrete actions, and pads them with motivational fluff ('A well-designed tool is the difference between an agent that works and one that hallucinates, fails silently, or costs 10x more tokens'). It is not score 4 because the listed items are topics, not executable actions, and the text is cut off mid-word ('more important than tool implementa').

Completeness

It answers 'what' clearly ('This skill covers tool design from schema to error handling') but contains no 'Use when...' clause or equivalent trigger guidance, capping completeness at 3 per the rubric guideline. It is not score 2 because the 'what' is concrete and multi-part, not vague.

Trigger Term Quality

Relevant keywords like 'tool design', 'JSON Schema', 'error handling', 'validation', and 'MCP' are present, but common natural variations users would say — 'function calling', 'tool use', 'build agent tools' — are missing. It does not reach score 4 because the keyword set lacks the synonyms and variation coverage of the higher anchor.

Distinctiveness Conflict Risk

The niche of AI-agent tool design with MCP and JSON Schema specifics ('Tool descriptions are more important than tool implementa...') is mostly distinct, with only minor overlap risk against closely related skills like api-designer or backend. It is not score 5 because without any 'when to use' phrasing, disambiguation from those overlapping skills relies entirely on domain keywords.