nix-best-practices
Nix patterns for flakes, overlays, unfree handling, and binary overlays. Use when working with flake.nix or shell.nix.
87
Quality
84%
Does it follow best practices?
Impact
91%
1.59xAverage score across 3 eval scenarios
Passed
No known issues
Quality
Discovery
89%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 solid skill description with excellent trigger terms and clear distinctiveness for the Nix ecosystem. The main weakness is that it describes topics/patterns rather than concrete actions Claude will perform. Adding action verbs like 'configure', 'create', or 'troubleshoot' would strengthen the specificity.
Suggestions
Add concrete action verbs to describe what Claude does with these patterns, e.g., 'Configure and troubleshoot Nix flakes, create overlays, handle unfree packages...'
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (Nix) and lists some specific concepts (flakes, overlays, unfree handling, binary overlays), but doesn't describe concrete actions like 'create', 'configure', or 'debug'. It describes patterns/topics rather than what Claude will do with them. | 2 / 3 |
Completeness | Answers both what (Nix patterns for flakes, overlays, unfree handling, binary overlays) and when (Use when working with flake.nix or shell.nix) with an explicit 'Use when...' clause. | 3 / 3 |
Trigger Term Quality | Includes natural keywords users would say: 'flakes', 'overlays', 'flake.nix', 'shell.nix', 'unfree'. These are terms Nix users commonly use when seeking help with Nix configuration. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive with Nix-specific terminology (flakes, overlays, flake.nix, shell.nix) that wouldn't conflict with other skills. The niche is clearly defined for Nix package management. | 3 / 3 |
Total | 11 / 12 Passed |
Implementation
79%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a strong, actionable Nix reference with excellent code examples and efficient prose. The main weaknesses are the lack of integrated validation checkpoints in multi-step workflows (particularly binary overlay creation) and the monolithic structure that could benefit from progressive disclosure to separate files for advanced topics.
Suggestions
Integrate hash verification as an explicit step in the binary overlay workflow (e.g., '1. Fetch URL, 2. Generate hash with nix-prefetch-url, 3. Verify hash matches, 4. Add to sources')
Split the binary overlay pattern and troubleshooting sections into separate referenced files (e.g., BINARY_OVERLAYS.md, TROUBLESHOOTING.md) to improve progressive disclosure
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is lean and efficient, presenting code examples without unnecessary explanation of what Nix is or how package managers work. Every section provides actionable patterns without padding. | 3 / 3 |
Actionability | Provides fully executable, copy-paste ready Nix code throughout. Examples are complete with proper syntax, and commands section gives exact CLI invocations for common operations. | 3 / 3 |
Workflow Clarity | While individual patterns are clear, the binary overlay creation workflow lacks explicit validation steps. The 'Getting SHA256 Hashes' section is separate from the pattern rather than integrated as a checkpoint in the workflow. | 2 / 3 |
Progressive Disclosure | Content is well-organized with clear sections, but it's a monolithic document (~250 lines) that could benefit from splitting advanced topics (binary overlays, troubleshooting) into separate files with references from the main skill. | 2 / 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.
- Repository
- NeverSight/skills_feed
- Commit
5342bca
- Reviewed
Table of Contents
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