defense-in-depth-validation
Validate at every layer data passes through to make bugs impossible. Use when invalid data causes failures deep in execution, requiring validation at multiple system layers.
Install with Tessl CLI
npx tessl i github:secondsky/claude-skills --skill defense-in-depth-validationOverall
score
77%
Does it follow best practices?
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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 explicit 'what' and 'when' clauses, earning full marks for completeness. However, it lacks specific concrete actions (what validation techniques?) and could benefit from more natural trigger terms users would actually say. The domain is somewhat generic and could conflict with related skills around testing or error handling.
Suggestions
Add specific validation actions like 'validate input schemas, sanitize user data, enforce type constraints, check API response formats'
Include more natural trigger terms users would say: 'input validation', 'data sanitization', 'type checking', 'schema validation', 'defensive coding'
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (data validation) and mentions 'validate at every layer' but lacks concrete specific actions like 'validate input schemas', 'sanitize user data', or 'type-check API responses'. | 2 / 3 |
Completeness | Clearly answers both what ('Validate at every layer data passes through to make bugs impossible') and when ('Use when invalid data causes failures deep in execution, requiring validation at multiple system layers') with explicit trigger guidance. | 3 / 3 |
Trigger Term Quality | Includes some relevant terms like 'validation', 'invalid data', 'bugs', and 'system layers', but misses common user phrases like 'input validation', 'data sanitization', 'type checking', 'schema validation', or 'defensive programming'. | 2 / 3 |
Distinctiveness Conflict Risk | The concept of 'validation' could overlap with skills for testing, error handling, or type systems. The phrase 'multiple system layers' adds some distinction but the scope remains somewhat broad. | 2 / 3 |
Total | 9 / 12 Passed |
Implementation
77%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 skill with excellent actionability through concrete, executable code examples and clear workflow guidance. The main weakness is some verbosity in the explanatory sections that could be trimmed, and the content could benefit from splitting the detailed example into a separate reference file. The four-layer pattern is well-documented with practical application steps.
Suggestions
Trim the 'Overview' and 'Why Multiple Layers' sections - combine into 2-3 sentences since the concept is straightforward
Consider moving the detailed 'Example from Session' to a separate EXAMPLES.md file and linking to it
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is mostly efficient but includes some explanatory text that could be tightened. Phrases like 'When you fix a bug caused by invalid data, adding validation at one place feels sufficient' explain concepts Claude understands. The 'Why Multiple Layers' section is somewhat redundant with the overview. | 2 / 3 |
Actionability | Provides fully executable TypeScript code examples for each validation layer. The code is copy-paste ready with clear patterns showing exactly what to validate and how to throw appropriate errors. | 3 / 3 |
Workflow Clarity | The 'Applying the Pattern' section provides a clear 4-step sequence with explicit validation at each checkpoint. The concrete example traces data flow through all layers and shows how each layer catches different failure modes. | 3 / 3 |
Progressive Disclosure | Content is well-structured with clear sections, but everything is inline in a single file. For a skill of this length (~100 lines), some content like the detailed example could be split to a separate file. However, the organization is logical and navigable. | 2 / 3 |
Total | 10 / 12 Passed |
Validation
81%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 13 / 16 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
metadata_version | 'metadata' field is not a dictionary | Warning |
license_field | 'license' field is missing | Warning |
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
Total | 13 / 16 Passed | |
- Reviewed
Table of Contents
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