Conciseness

The body is tight — compact code snippets, no explanations of concepts Claude already knows — but it repeats the frontmatter description verbatim and ends with a vacuous filler section ('This skill is applicable to execute the workflow or actions described in the overview.'). These are minor instances that could be trimmed, so it sits at 4 rather than 5.

Actionability

Auth patterns, response-model snippets, status-code usage, and integration paths are concrete, but the Quick Start's primary instruction — 'Copy the template from assets/template.py' — references a file that does not exist in the bundle, and the snippets are incomplete fragments (no imports, '...' bodies). The core workflow cannot actually be executed as written, which fits the 'concrete guidance but incomplete / missing key details' anchor rather than 4.

Workflow Clarity

'Integration Steps' is a clear, concrete 5-step sequence with real paths ('src/backend/app/routers/', 'src/backend/app/main.py'). It falls short of 5 because there is no verification step (e.g., start the app or run tests to confirm the router mounts), but the steps are specific enough to exceed the 'checkpoints missing' anchor at 3.

Progressive Disclosure

Scored against the actual bundle structure: no references/, scripts/, or assets/ directories exist, yet the body directs readers to 'assets/template.py' — a dangling reference that breaks navigation at the skill's entry point. In-body section organization is good, but a broken primary reference is more than a 'minor organization gap', so it cannot score 4.

Specificity

Names the domain ('FastAPI routers') and enumerates three concrete concerns — 'proper authentication, response models, and HTTP status codes' — leaving only minor coverage gaps. It falls short of 5 because 'following established patterns' is vague padding and broader coverage (mounting, testing, Pydantic models) is absent.

Completeness

The 'what' is clear, but the description contains no 'Use when...' clause or equivalent explicit trigger guidance, capping completeness at 3 per the judging guidelines. Not 4 because nothing in the text implies when to invoke the skill.

Trigger Term Quality

Includes natural terms a FastAPI developer would actually say: 'FastAPI', 'routers', 'authentication', 'response models', 'HTTP status codes'. A few natural variations ('endpoints', 'routes', 'add an API') are missing, keeping it below 5.

Distinctiveness Conflict Risk

'FastAPI routers' carves a mostly distinct niche with minor overlap risk against broader API-development skills. Not 5 because distinctiveness rests on one phrase and 'authentication... HTTP status codes' overlaps with general backend skills.