Conciseness

The ~55-line body is lean: no concept explanations Claude already knows, no padding — every element (architecture diagram, Quick Reference table, Start Here paths) routes to a specific reference file. It matches anchor 5 ('every token earns its place') with nothing trimmable down to anchor 4.

Actionability

Concrete, executable routing: 'Check Deliverability first—authentication problems are the most common cause. Gmail/Yahoo reject unauthenticated emails', plus ordered paths like 'Email Capture (collect consent) → Compliance (legal requirements) → Marketing Emails'. Falls short of anchor 5 because the body contains no copy-paste-ready code or commands (e.g., a sample SPF DNS record) — all executable detail is deferred one file deep; per the scoring notes, the absence of code itself is not penalized, only the missing quick-start snippet.

Workflow Clarity

Multi-step processes are clearly sequenced: the architecture diagram shows a pre-send checkpoint ('Suppression Check' before 'Ready to Send') and feedback loops (Bounced/Complained events → 'Suppression List Updated' → 'List Hygiene Jobs'), and Start Here gives ordered reading paths. Not anchor 5 because the task paths carry no explicit verification steps of their own (deferred to references); not anchor 3 because checkpoints are shown, not merely implicit.

Progressive Disclosure

Exemplary router structure: a Quick Reference table mapping 11 needs to 11 files, task-based entry paths in Start Here, and one-level-deep references — all 11 referenced files verified present in references/ with substantive content, with no missing or orphaned files. Matches anchor 5 exactly.

Specificity

The description enumerates multiple concrete, specific items — 'setting up SPF/DKIM/DMARC authentication', 'implementing email capture', 'ensuring compliance (CAN-SPAM, GDPR, CASL)', 'handling webhooks, retry logic', 'making emails accessible (alt text, headings, contrast, screen readers)', 'deciding transactional vs marketing' — with comprehensive coverage across deliverability, capture, compliance, reliability, and accessibility. It exceeds anchor 4 ('minor gaps in coverage') because no significant email-domain concern is left out.

Completeness

The entire description is a single 'Use when…' clause — the 'when' is thorough, but no 'what' statement exists (nothing says the skill provides guidance, code, or checks). This matches anchor 2's 'only when is present without what' clause exactly, and the guidelines forbid inferring a 'what' that would justify anchor 3.

Trigger Term Quality

It uses natural phrases users actually say ('emails going to spam', 'high bounce rates') alongside synonym clusters ('alt text, headings, contrast, screen readers') and named regulations, matching the comprehensive-with-synonyms anchor 5. It is above anchor 4 because no common natural phrasing for the domain is conspicuously missing.

Distinctiveness Conflict Risk

Distinctive email-specific triggers (SPF/DKIM/DMARC, CAN-SPAM/GDPR/CASL, transactional vs marketing) establish a clear niche, but the generic items 'handling webhooks, retry logic' could fire for non-email webhook/retry questions — minor overlap risk with closely related skills, per anchor 4. Not anchor 5 because those generic triggers are not fully scoped to email.