Content
64%Scale 1-3Reviews 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. Its main weaknesses are moderate verbosity (explaining concepts Claude likely knows, like HTTP status codes and REST conventions) and a lack of sequential workflow structure — it reads more like a reference guide than a step-by-step process. The content would benefit from splitting into a concise overview with references to detailed pattern files.
Suggestions
Trim explanations of concepts Claude already knows well (HTTP status code meanings, what PATCH vs PUT does, basic REST conventions) to reduce token usage by ~30%.
Add a brief sequential workflow at the top: 1. Define contract types → 2. Design resource URLs → 3. Define error format → 4. Add validation at boundaries → 5. Run verification checklist.
Split REST API Patterns and TypeScript Interface Patterns into separate referenced files to improve progressive disclosure and reduce the main file's length.
| 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, discriminated unions, branded types, and concrete REST endpoint patterns. All examples are copy-paste ready and specific. | 3 / 3 |
Workflow Clarity | The verification checklist at the end provides a good summary checkpoint, but the skill lacks a clear sequential workflow for designing an API. The principles are presented as independent sections rather than a sequenced process. For a design-oriented skill this is partially acceptable, but there's no explicit 'do this, then validate, then proceed' flow. | 2 / 3 |
Progressive Disclosure | The content is well-organized with clear headers and sections, 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. The one reference to 'deprecation-and-migration' suggests awareness of progressive disclosure but the main file carries too much inline detail. | 2 / 3 |
Total | 9 / 12 Passed |