Names the domain (FastAPI) and some patterns (async patterns, dependency injection, error handling), but doesn't list multiple concrete actions like 'create routes, configure middleware, set up database models'. The actions are more about qualities of the output than specific tasks.

Clearly answers both 'what' (create production-ready FastAPI projects with async patterns, dependency injection, error handling) and 'when' (when building new FastAPI applications or setting up backend API projects) with an explicit 'Use when' clause.

Includes 'FastAPI', 'backend API', and 'API projects' which are relevant keywords, but misses common variations users might say like 'REST API', 'Python API', 'web server', 'endpoints', 'ASGI', or 'uvicorn'.

FastAPI is a specific framework, making this clearly distinguishable from general Python skills, Django skills, or Flask skills. The triggers are distinct enough to avoid conflicts with other skills.

Extremely verbose at ~400+ lines. The 'Core Concepts' section explains DI, async patterns, and project structure concepts Claude already knows. The 'When to Use This Skill' section is unnecessary padding. Much of the code could be condensed or split into referenced files.

The code examples are fully executable and copy-paste ready, covering the complete stack from main.py through repositories, services, endpoints, security, and testing. Concrete patterns with real imports and type annotations.

There is no sequenced workflow for setting up a project. The skill presents patterns but never says 'Step 1: create config, Step 2: set up database, Step 3: create models...' There are no validation checkpoints, no verification steps, and no guidance on order of operations for building the project.

Monolithic wall of code with no references to external files. All patterns are inlined in a single massive document. The project structure, repository pattern, service layer, auth, and testing could each be separate referenced files with a concise overview in the main skill.