Verify that interface and class contracts (preconditions, postconditions, invariants) are preserved across program versions. Use when validating refactorings, checking API compatibility, verifying design-by-contract implementations, or ensuring behavioral contracts remain intact after code changes. Automatically detects contract violations, identifies affected methods and classes, and provides actionable guidance for resolving violations while maintaining program correctness.
90
86%
Does it follow best practices?
Impact
95%
2.02xAverage score across 3 eval scenarios
Passed
No known issues
Quality
Discovery
100%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
This is a well-crafted skill description that excels across all dimensions. It provides specific concrete actions, includes an explicit 'Use when...' clause with natural trigger terms, and occupies a distinct niche (contract verification) that minimizes conflict risk with other skills. The description uses proper third-person voice throughout.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: 'Verify interface and class contracts', 'detects contract violations', 'identifies affected methods and classes', 'provides actionable guidance for resolving violations'. Covers preconditions, postconditions, and invariants explicitly. | 3 / 3 |
Completeness | Clearly answers both what (verify contracts, detect violations, identify affected code, provide guidance) AND when (explicit 'Use when' clause covering validating refactorings, checking API compatibility, verifying design-by-contract, ensuring contracts after code changes). | 3 / 3 |
Trigger Term Quality | Includes natural keywords users would say: 'refactorings', 'API compatibility', 'design-by-contract', 'contract violations', 'behavioral contracts', 'code changes'. Good coverage of domain-specific terms that developers would naturally use. | 3 / 3 |
Distinctiveness Conflict Risk | Highly specific niche focused on contract verification and design-by-contract paradigm. Terms like 'preconditions', 'postconditions', 'invariants', and 'contract violations' are distinct and unlikely to conflict with general code review or testing skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
72%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This skill is well-organized and concise, effectively covering contract verification concepts without over-explaining. However, it lacks concrete validation steps in the workflow and the resolution guidance is too abstract to be immediately actionable. The dependency on external scripts without showing expected outputs or error handling weakens practical usability.
Suggestions
Add example output from contract_verifier.py showing what a violation report looks like in report.json
Include a validation/feedback loop in the workflow: what to do if verification finds violations, how to iterate
Make resolution guidance more concrete with before/after code examples showing how to fix each violation type
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is lean and efficient, assuming Claude understands programming concepts like preconditions and postconditions. No unnecessary explanations of basic concepts; every section serves a clear purpose. | 3 / 3 |
Actionability | Provides concrete bash commands and Python docstring examples, but the scripts referenced (contract_extractor.py, contract_verifier.py) are external dependencies without showing their actual implementation or output format. The resolution guidance is abstract rather than executable. | 2 / 3 |
Workflow Clarity | The 3-step workflow is clearly sequenced, but lacks validation checkpoints. No feedback loop for handling verification failures, no guidance on what to do if extraction fails, and 'Review Violations' step is vague without concrete next actions. | 2 / 3 |
Progressive Disclosure | Well-structured with clear sections progressing from workflow to concepts to resolution. References to external files (design_by_contract.md, scripts) are one level deep and clearly signaled in the Resources section. | 3 / 3 |
Total | 10 / 12 Passed |
Validation
100%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 11 / 11 Passed
Validation for skill structure
No warnings or errors.
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Table of Contents
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