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.

1.13x

Quality

44%

Does it follow best practices?

Impact

94%

1.13x

Average score across 3 eval scenarios

Securityby

Passed

No known issues

Optimize this skill with Tessl

npx tessl skill review --optimize ./tests/ext_conformance/artifacts/agents-wshobson/backend-development/skills/api-design-principles/SKILL.md

Quality

Content

22%

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

This skill reads like a comprehensive API design tutorial rather than an efficient skill file for Claude. It is excessively verbose, explaining many concepts Claude already knows (HTTP methods, REST principles, GraphQL basics), and lacks any clear workflow or sequenced process for the tasks it claims to support. The code examples provide some value but reference nonexistent helper functions and nonexistent bundle files, undermining both actionability and progressive disclosure.

Suggestions

Drastically reduce content to only what Claude doesn't already know—remove explanations of HTTP methods, basic REST/GraphQL concepts, and common pitfalls that are general knowledge. Focus on project-specific conventions and opinionated decisions.

Add a clear step-by-step workflow for the primary use case (e.g., 'Designing a new API') with explicit checkpoints like schema review, validation against a checklist, and iterative refinement steps.

Move the detailed code patterns (pagination, error handling, DataLoader, HATEOAS) into actual bundle reference files and keep SKILL.md as a concise overview with pointers to those files.

Make code examples self-contained and executable by either providing the missing helper functions or replacing them with inline implementations that can actually run.

Dimension	Reasoning	Score
Conciseness	Extremely verbose at ~400+ lines. Explains concepts Claude already knows well (REST methods, HTTP semantics, what GraphQL is, resource-oriented architecture). The 'When to Use This Skill' section, 'Core Concepts' rehashing HTTP methods, and 'Common Pitfalls' bullet list are all padding that adds no novel knowledge for Claude.	1 / 3
Actionability	Contains concrete Python/GraphQL code examples that are mostly executable (FastAPI endpoints, Pydantic models, Ariadne resolvers, DataLoaders). However, many examples reference undefined functions (build_query, fetch_users, count_users, etc.) making them not truly copy-paste ready, and the skill reads more like a tutorial/reference than actionable instructions for a specific task.	2 / 3
Workflow Clarity	There is no clear workflow or sequenced process. The skill presents patterns and best practices as a reference document but never defines a step-by-step process for designing an API, reviewing a spec, or any of its stated use cases. No validation checkpoints or feedback loops are present.	1 / 3
Progressive Disclosure	References to external files (references/rest-best-practices.md, assets/rest-api-template.py, scripts/openapi-generator.py, etc.) are listed in a Resources section, but none of these files exist in the bundle. The main content is a monolithic wall of code and text that should have been split across referenced files, with only a concise overview in SKILL.md.	2 / 3
	Total	6 / 12 Passed

Description

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 and identifies its domain clearly (REST and GraphQL API design). However, it relies on vague aspirational language ('delight developers', 'intuitive, scalable, and maintainable') instead of listing concrete capabilities, and it could benefit from more natural trigger terms that users would actually use when seeking API design help.

Suggestions

Replace vague aspirational language ('delight developers', 'intuitive, scalable, and maintainable') with concrete actions like 'define resource naming conventions, design pagination, structure error responses, plan versioning strategies'.

Add more natural trigger terms users would say, such as 'endpoints', 'routes', 'OpenAPI', 'swagger', 'schema', 'versioning', 'rate limiting', or 'error codes'.

Dimension	Reasoning	Score
Specificity	Names the domain (REST and GraphQL API design) and mentions some actions ('designing new APIs, reviewing API specifications, establishing API design standards'), but the core description uses vague aspirational language ('intuitive, scalable, and maintainable APIs that delight developers') rather than listing concrete specific actions like 'define resource naming conventions, design pagination schemes, structure error responses'.	2 / 3
Completeness	Clearly answers both 'what' (REST and GraphQL API design principles) and 'when' with an explicit 'Use when...' clause covering three trigger scenarios: designing new APIs, reviewing API specifications, or establishing API design standards.	3 / 3
Trigger Term Quality	Includes some relevant keywords like 'REST', 'GraphQL', 'API design', 'API specifications', and 'API design standards', but misses common natural variations users might say such as 'endpoints', 'routes', 'OpenAPI', 'swagger', 'schema design', 'versioning', 'pagination', or 'error handling'.	2 / 3
Distinctiveness Conflict Risk	The focus on API design principles for REST and GraphQL provides some distinctiveness, but 'designing new APIs' and 'reviewing API specifications' could overlap with general coding skills, backend development skills, or OpenAPI/Swagger-specific skills. The phrase 'delight developers' is fluffy and doesn't aid disambiguation.	2 / 3
	Total	9 / 12 Passed

Validation

90%

Warnings & errors only

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

Repository: Dicklesworthstone/pi_agent_rust
Commit: 2cab08a

Reviewed: about 23 hours ago

Table of Contents

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