nix-profile-manager
Expert guidance for agents to manage local Nix profiles for installing tools and dependencies. Covers flakes, profile management, package searching, and registry configuration.
62
48%
Does it follow best practices?
Impact
74%
1.42xAverage score across 3 eval scenarios
Advisory
Suggest reviewing before use
Optimize this skill with Tessl
npx tessl skill review --optimize ./nix-profile-manager/SKILL.mdQuality
Discovery
32%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 identifies the Nix ecosystem domain and lists relevant topic areas but lacks concrete actions and explicit trigger guidance. It reads more like a table of contents than a discriminating skill description. The absence of a 'Use when...' clause significantly weakens its utility for skill selection among many options.
Suggestions
Add an explicit 'Use when...' clause, e.g., 'Use when the user asks about installing packages with Nix, managing nix profiles, configuring flake inputs, or searching nixpkgs.'
Replace topic-area listings with concrete actions, e.g., 'Installs packages via nix profile install, searches nixpkgs for available packages, configures flake registries, and manages local Nix profile generations.'
Include common user-facing trigger terms and file/command references like 'nix profile', 'nix search', 'flake.nix', 'nixpkgs', 'nix-env' to improve keyword matching.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (Nix profiles) and lists some areas (flakes, profile management, package searching, registry configuration), but these are more like topic areas than concrete actions. It doesn't specify what actions are performed, e.g., 'install packages via nix profile install', 'search nixpkgs', 'configure flake registries'. | 2 / 3 |
Completeness | It describes what the skill covers at a high level but has no explicit 'Use when...' clause or equivalent trigger guidance. Per the rubric, a missing 'Use when...' clause should cap completeness at 2, and since the 'what' is also somewhat vague, this scores a 1. | 1 / 3 |
Trigger Term Quality | Includes relevant keywords like 'Nix', 'flakes', 'profile', 'package searching', and 'registry' which users familiar with Nix would use. However, it misses common variations like 'nix-env', 'nixpkgs', 'nix install', 'nix shell', or 'nix develop' that users might naturally say. | 2 / 3 |
Distinctiveness Conflict Risk | The mention of 'Nix profiles' and 'flakes' provides some distinctiveness from general package management skills, but 'installing tools and dependencies' is generic enough to potentially overlap with other package manager or dependency management skills. | 2 / 3 |
Total | 7 / 12 Passed |
Implementation
64%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, actionable skill with executable commands and good structural organization. Its main weaknesses are moderate verbosity in the conceptual sections (explaining flakes and profiles at a level Claude doesn't need), missing validation steps after installations, and references to bundle files that don't exist. The command examples are its strongest asset.
Suggestions
Trim the 'Core Concepts' section significantly — Claude already understands what flakes and profiles are; focus only on non-obvious details like nested package paths and the `add` vs `install` version difference.
Add an explicit validation step after installation in the workflow, e.g., `nix profile list --profile "$AGENT_PROFILE" | grep git` or `which git` to confirm the tool is available.
Either provide the referenced bundle files (references/flakes.md, etc.) or remove the References section to avoid pointing to non-existent resources.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill includes some unnecessary explanations (e.g., explaining what profiles and flakes are conceptually, which Claude already knows), and the 'Core Concepts' section is somewhat verbose. However, the command sections are reasonably lean and the overall structure isn't excessively padded. | 2 / 3 |
Actionability | The skill provides fully executable bash commands throughout, with concrete examples for searching, installing, listing, removing, and upgrading packages. The commands are copy-paste ready with clear placeholder conventions. | 3 / 3 |
Workflow Clarity | The 'General Workflow' section provides a clear sequence, and the troubleshooting section helps with error recovery. However, there are no explicit validation checkpoints — after installing a package, there's no step to verify the installation succeeded (e.g., checking the binary exists in PATH or running `nix profile list` to confirm). | 2 / 3 |
Progressive Disclosure | The References section lists four supporting files with clear descriptions, which is good structure. However, no bundle files were provided, meaning these references point to non-existent files. Additionally, the Core Concepts section contains substantial inline content that could be offloaded to reference files, making the main skill leaner. | 2 / 3 |
Total | 9 / 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
- YPares/agent-skills
- Commit
84b1da5
- Reviewed
Table of Contents
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