Content
64%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a solid, actionable API design skill with excellent concrete examples and good coverage of important patterns (contract-first, boundary validation, error semantics, Hyrum's Law). Its main weaknesses are moderate verbosity — some content explains things Claude already knows — and a monolithic structure that could benefit from splitting into focused sub-files. The verification checklist is a strength but would be more effective integrated into a clearer design workflow.
Suggestions
Trim explanations of well-known concepts (HTTP status codes, PATCH vs PUT semantics) to brief reminders rather than full explanations, saving significant token budget.
Split REST API patterns and TypeScript interface patterns into separate referenced files, keeping SKILL.md as a concise overview with links to detailed guides.
Add a brief sequenced workflow (e.g., '1. Define contract types → 2. Design error format → 3. Add validation at boundaries → 4. Run verification checklist') to improve workflow clarity.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is generally well-structured but includes some content Claude already knows (e.g., HTTP status code meanings, basic REST conventions, what PATCH vs PUT means). The 'Common Rationalizations' table, while useful, adds bulk. The Hyrum's Law explanation is somewhat verbose. However, the code examples are tight and the tables are efficient. | 2 / 3 |
Actionability | The skill provides fully executable TypeScript code examples throughout — contract-first interface definitions, validation at boundaries with real Zod-style parsing, REST resource design patterns, discriminated unions, and branded types. All examples are concrete and copy-paste ready. | 3 / 3 |
Workflow Clarity | The skill provides a verification checklist at the end, which is good, but lacks a clear sequenced workflow for the API design process itself. The principles are presented as independent sections rather than a step-by-step process. For a design skill this is partially acceptable, but the checklist could be better integrated as validation checkpoints within a workflow. | 2 / 3 |
Progressive Disclosure | The content is well-organized with clear sections and headers, but it's a long monolithic document (~200+ lines of substantive content) that could benefit from splitting REST patterns, TypeScript patterns, and core principles into separate referenced files. There is one reference to 'deprecation-and-migration' but no other external references or bundle files to support progressive disclosure. | 2 / 3 |
Total | 9 / 12 Passed |