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package-npm-nix

Package npm/TypeScript/Bun CLI tools for Nix. Use when creating Nix derivations for JavaScript/TypeScript tools from npm registry or GitHub sources, handling pre-built packages or source builds with dependency management.

92

1.63x
Quality

88%

Does it follow best practices?

Impact

100%

1.63x

Average score across 3 eval scenarios

SecuritybySnyk

Advisory

Suggest reviewing before use

SKILL.md
Quality
Evals
Security

Quality

Content

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 strong, highly actionable skill with complete executable templates for both pre-built and source-build npm packaging in Nix. The workflow is well-sequenced with proper validation steps and a comprehensive checklist. The main weakness is that the document is somewhat long and monolithic—some sections (troubleshooting, anti-patterns, metadata requirements) could be trimmed or split into referenced files, and a few explanations are unnecessary for Claude's knowledge level.

Suggestions

Trim the anti-patterns section—Claude doesn't need explanations like why chmod +x is needed or why lib.fakeHash is insecure; a brief list of do/don't pairs would suffice.

Consider splitting troubleshooting and metadata requirements into separate referenced files to reduce the main skill's token footprint.

DimensionReasoningScore

Conciseness

The skill is fairly comprehensive but includes some unnecessary verbosity. The objective section restates what the skill title already conveys, the source provenance guide explains concepts Claude would know, and some sections like anti-patterns belabor obvious points (e.g., explaining why you need chmod +x). However, most content is substantive and pattern-focused rather than tutorial-style.

2 / 3

Actionability

Excellent actionability with fully executable Nix derivation templates, concrete bash commands for hash fetching, complete code examples for both pre-built and source build approaches, and specific patterns for handling WASM files, multiple executables, and native dependencies. All code is copy-paste ready with clear placeholder values.

3 / 3

Workflow Clarity

The workflow is clearly sequenced across 5 steps with explicit validation checkpoints: step 2 includes hash verification iteration, step 5 includes build testing with ldd checks, and the build phase includes lockfile verification (diff -q). The validation section provides a comprehensive checklist, and the troubleshooting section covers common failure modes with clear recovery steps.

3 / 3

Progressive Disclosure

The content is well-structured with clear sections (quick_start, workflow, common_patterns, troubleshooting, validation), but it's a monolithic document that could benefit from splitting detailed reference material (troubleshooting, anti-patterns, special cases) into separate files. No bundle files are provided, and no external references are made, so all ~300+ lines live in one file.

2 / 3

Total

10

/

12

Passed

Description

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 strong skill description that clearly defines a specific niche (Nix packaging for JS/TS CLI tools), includes an explicit 'Use when' clause with relevant trigger terms, and is distinctive enough to avoid conflicts with related skills. The description is concise yet comprehensive, covering the what, when, and key variations (npm registry vs GitHub, pre-built vs source builds).

DimensionReasoningScore

Specificity

Lists multiple concrete actions: 'Package npm/TypeScript/Bun CLI tools for Nix', 'creating Nix derivations', 'handling pre-built packages or source builds with dependency management'. These are specific, actionable capabilities.

3 / 3

Completeness

Clearly answers both what ('Package npm/TypeScript/Bun CLI tools for Nix') and when ('Use when creating Nix derivations for JavaScript/TypeScript tools from npm registry or GitHub sources, handling pre-built packages or source builds with dependency management'). Has explicit 'Use when' clause.

3 / 3

Trigger Term Quality

Includes strong natural keywords users would say: 'npm', 'TypeScript', 'Bun', 'CLI tools', 'Nix', 'Nix derivations', 'JavaScript', 'npm registry', 'GitHub sources', 'pre-built packages', 'source builds', 'dependency management'. Good coverage of variations.

3 / 3

Distinctiveness Conflict Risk

Very specific niche at the intersection of Nix packaging and npm/TypeScript/Bun CLI tools. The combination of Nix + npm/JS ecosystem packaging is highly distinctive and unlikely to conflict with general Nix skills or general npm skills.

3 / 3

Total

12

/

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.

Validation10 / 11 Passed

Validation for skill structure

CriteriaDescriptionResult

skill_md_line_count

SKILL.md is long (591 lines); consider splitting into references/ and linking

Warning

Total

10

/

11

Passed

Repository
YPares/agent-skills
Reviewed

Table of Contents

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