Conciseness

The body is mostly efficient — tight tables, a compact syntax block, and two focused code examples — but the 'Notes' section is almost entirely duplication: 'TemplateType is either Standard or Layout', 'Layout inheritance: Standard template body replaces {{{@content}}}', 'Maximum 100 templates per server', and 'Template validation (/templates/validate)...' all restate facts already covered in the feature table, Template Types section, and Common Mistakes table. This fits the 3 anchor (mostly efficient but could be tightened); it is not the 2 anchor because there is no explanation of concepts Claude already knows and the padding is confined to one compact section.

Actionability

The guidance is largely executable — a complete endpoints table, a copy-paste-ready ServerClient example with TemplateAlias/TemplateModel, and a working validateTemplate snippet — meeting the 5 anchor in form. However, the inline Handlebars cheat-sheet shows '{{#if premium}}' and '{{#each items}}', which the skill's own references/handlebars-syntax.md states are unsupported ('Mustachio... does not support {{#if}}'), leaving the reader with contradictory instructions. That minor gap in reliable, executable guidance places it at the 4 anchor rather than 5.

Workflow Clarity

The 'Quick Start' sequence (create template, define variables, send with /email/withTemplate, pass TemplateModel) is clear, and validation appears both as a dedicated 'Validate a Template' section ('useful in CI/CD before deploying') and in the Common Mistakes table ('Not validating before deploy'). This fits the 4 anchor — clear sequence with most checkpoints present — but not the 5 anchor, because validation is never wired into the workflow as an explicit ordered step with an error-recovery loop, and batch (500 emails) and destructive (DELETE, push-to-production) operations lack feedback-loop guidance.

Progressive Disclosure

SKILL.md is a genuine overview with the essentials inline, and all three referenced files (references/handlebars-syntax.md, references/layout-templates.md, references/template-api.md) exist, are one level deep, and are clearly signaled with descriptive links ('for the full syntax reference including conditionals, iteration with index...', 'for full CRUD operations (create, list, update, delete), batch sending, validate, and push'). This matches the 5 anchor: appropriate split, easy navigation, well-signaled one-level-deep references.

Specificity

The description enumerates multiple concrete capabilities — 'creating, managing, or sending', 'Handlebars syntax, layout inheritance, template validation, and cross-server pushing' — giving comprehensive, specific coverage of the skill's actions rather than vague domain language. It clearly matches the 5 anchor ('lists multiple specific concrete actions; comprehensive coverage') and not the 4 anchor, which requires minor gaps in coverage.

Completeness

Both questions are explicitly answered: 'when' via the leading 'Use when creating, managing, or sending with Postmark...' trigger clause, and 'what' via the concrete topic enumeration 'Handlebars syntax, layout inheritance, template validation, and cross-server pushing'. This matches the 5 anchor (explicit what AND when with concrete trigger phrases); the 'Use when' clause is present, so the completeness cap of 3 does not apply.

Trigger Term Quality

It includes strong natural terms users would say — 'Postmark', 'email templates', 'Handlebars', 'sending' — but misses common variations like 'transactional email' or 'email merge fields'. Good keyword coverage with a few natural terms missing fits the 4 anchor; the 5 anchor requires synonym/extension-level coverage that is not quite met.

Distinctiveness Conflict Risk

'Postmark server-side email templates' carves out a clear niche with distinct product-specific triggers; virtually no other skill would fire on these terms. This matches the 5 anchor (clear niche, minimal conflict risk) rather than the 4 anchor, which requires some overlap risk with closely related skills.