Conciseness

Lean and efficient: no explanation of concepts Claude already knows, tight command examples, a compact flag table, and concise Notes; nearly every token earns its place (only a minor one-line intro restate).

Actionability

Fully executable, copy-paste ready bash commands covering search/read/info/attachment/mailboxes, plus a complete flag reference table and explicit output-format spec with concrete IDs and addresses.

Workflow Clarity

A simple, single-purpose read-only tool ("never modifies mail data") with an unambiguous search -> info/read -> attachment flow and well-organized sections, qualifying for the simple-skill exception; the destructive/batch validation cap does not apply.

Progressive Disclosure

A single self-contained SKILL.md (~68 lines) with no external bundle files and clear, navigable sections (Quick Reference, Search Options, Output Format, Notes); no nested references and no content that needs splitting.

Specificity

Lists multiple concrete actions (search, read, extract attachments) plus seven query dimensions and raw RFC822 handling, giving comprehensive capability coverage rather than several actions with minor gaps.

Completeness

The "what" is clear and concrete, but there is no "Use when..." or equivalent explicit trigger guidance, so per the rubric cap completeness cannot exceed 3.

Trigger Term Quality

Good natural keywords users would say ("Apple Mail", "emails", "attachments", "sender", "subject", "mailbox"), but missing common synonyms and file extensions ("Mail.app", ".emlx", "EMLX") for full coverage.

Distinctiveness Conflict Risk

Targets a specific platform (Apple Mail's local SQLite/.emlx storage) with distinct triggers and minimal overlap with other skills.