api-design-principles
Master REST and GraphQL API design principles to build intuitive, scalable, and maintainable APIs that delight developers. Use when designing new APIs, reviewing API specifications, or establishing API design standards.
Install with Tessl CLI
npx tessl i github:Dicklesworthstone/pi_agent_rust --skill api-design-principles66
Does it follow best practices?
If you maintain this skill, you can automatically optimize it using the tessl CLI to improve its score:
npx tessl skill review --optimize ./path/to/skillValidation for skill structure
Discovery
67%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
The description has a solid structure with an explicit 'Use when' clause that clearly defines trigger scenarios. However, it relies on vague marketing language ('delight developers', 'intuitive, scalable') instead of listing concrete capabilities, and could benefit from more natural trigger terms that users would actually say when needing API design help.
Suggestions
Replace vague qualifiers with specific actions like 'define resource naming conventions, design pagination strategies, structure error responses, version APIs'
Add more natural trigger terms users would say: 'endpoints', 'routes', 'OpenAPI', 'swagger', 'API documentation', 'request/response format'
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (REST and GraphQL API design) and mentions some actions (designing, reviewing, establishing standards), but uses vague qualifiers like 'intuitive, scalable, and maintainable' and 'delight developers' which are abstract rather than concrete capabilities. | 2 / 3 |
Completeness | Clearly answers both what (API design principles for REST and GraphQL) and when (designing new APIs, reviewing specifications, establishing standards) with an explicit 'Use when' clause containing specific triggers. | 3 / 3 |
Trigger Term Quality | Includes relevant keywords like 'REST', 'GraphQL', 'API design', 'API specifications', but misses common variations users might say such as 'endpoints', 'routes', 'schema', 'OpenAPI', 'swagger', or 'API documentation'. | 2 / 3 |
Distinctiveness Conflict Risk | Focuses on API design which is a specific niche, but could overlap with general coding skills, backend development skills, or documentation skills. The REST/GraphQL focus helps but 'API design standards' is somewhat broad. | 2 / 3 |
Total | 9 / 12 Passed |
Implementation
50%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
The skill provides excellent, executable code examples for both REST and GraphQL APIs, demonstrating strong actionability. However, it suffers from significant verbosity, explaining fundamental concepts Claude already knows (HTTP methods, REST principles, GraphQL basics). The content would benefit from aggressive trimming to focus on project-specific patterns and conventions, with detailed examples moved to reference files.
Suggestions
Remove explanatory content about basic concepts (HTTP methods, what REST/GraphQL are) and assume Claude's existing knowledge
Move detailed code patterns to separate reference files (e.g., rest-patterns.md, graphql-patterns.md) and keep SKILL.md as a concise overview with links
Add a clear workflow section with validation checkpoints for API design review (e.g., 'Before implementation: 1. Review schema against checklist, 2. Validate naming conventions, 3. Check pagination strategy')
Reduce the 'When to Use This Skill' section to 1-2 lines since it largely repeats the skill description
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | Extremely verbose at ~400 lines. Explains concepts Claude already knows (HTTP methods, what REST is, what GraphQL is). The 'When to Use This Skill' section repeats the description. Much content is textbook-level explanation rather than actionable guidance. | 1 / 3 |
Actionability | Provides fully executable Python/FastAPI code examples, complete GraphQL schemas, and copy-paste ready patterns. Code is concrete, typed, and includes real implementation details like DataLoaders and pagination. | 3 / 3 |
Workflow Clarity | Patterns are presented but lack clear sequencing for multi-step API design processes. No validation checkpoints for reviewing API designs before implementation. The 'Best Practices' and 'Common Pitfalls' are lists without workflow integration. | 2 / 3 |
Progressive Disclosure | References external files at the end (references/, assets/, scripts/) which is good, but the main content is a monolithic wall of text. Core concepts, patterns, and best practices could be split into separate files with SKILL.md as a concise overview. | 2 / 3 |
Total | 8 / 12 Passed |
Validation
90%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 10 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
skill_md_line_count | SKILL.md is long (529 lines); consider splitting into references/ and linking | Warning |
Total | 10 / 11 Passed | |
- Reviewed
Table of Contents
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