nushell-plugin-builder
Guide for creating Nushell plugins in Rust using nu_plugin and nu_protocol crates. Use when users want to build custom Nushell commands, extend Nushell with new functionality, create data transformations, or integrate external tools/APIs into Nushell. Covers project setup, command implementation, streaming data, custom values, and testing.
90
86%
Does it follow best practices?
Impact
95%
1.20xAverage score across 3 eval scenarios
Advisory
Suggest reviewing before use
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 strong skill description that clearly defines its niche (Nushell plugin development in Rust), lists concrete capabilities, and provides explicit trigger guidance via a 'Use when' clause. It uses third-person voice appropriately and includes both domain-specific terms and natural language triggers that developers would use.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: creating Nushell plugins in Rust, project setup, command implementation, streaming data, custom values, and testing. Also mentions specific crates (nu_plugin, nu_protocol). | 3 / 3 |
Completeness | Clearly answers both 'what' (guide for creating Nushell plugins in Rust covering project setup, command implementation, streaming data, custom values, testing) and 'when' (explicit 'Use when users want to build custom Nushell commands, extend Nushell with new functionality, create data transformations, or integrate external tools/APIs'). | 3 / 3 |
Trigger Term Quality | Includes strong natural keywords users would say: 'Nushell plugins', 'Rust', 'custom Nushell commands', 'extend Nushell', 'data transformations', 'integrate external tools/APIs', 'nu_plugin', 'nu_protocol'. Good coverage of terms a developer would use when seeking this functionality. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive niche: Nushell plugin development in Rust using specific crates. Very unlikely to conflict with other skills given the specificity of the domain (Nushell + Rust + plugin development). | 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 is a well-structured, highly actionable skill for building Nushell plugins in Rust. Its main strengths are complete executable code examples, good progressive disclosure with clear references to deeper documentation, and a logical flow from quick start to advanced features. Minor weaknesses include some verbosity in explanatory sections and missing validation checkpoints in the development workflow.
Suggestions
Add explicit validation/error-recovery steps to the development workflow (e.g., check cargo build exit code, verify plugin registration succeeded with `plugin list`, troubleshoot common registration failures).
Trim the Command Types and Serialization sections—the brief descriptions of when to use each are somewhat redundant given Claude's knowledge; a simple table or one-liner per option would suffice.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | Generally efficient but includes some unnecessary explanations (e.g., explaining what MsgPackSerializer vs JsonSerializer are, describing what SimplePluginCommand vs PluginCommand are for when the signatures make it clear). The serialization section and command types section could be tighter. However, most code examples are lean and purposeful. | 2 / 3 |
Actionability | Provides fully executable Rust code with complete imports, a working main function, cargo commands for building/installing, and concrete patterns for common operations (string transformation, list generation, records, tables). The quick start is copy-paste ready and the signature/argument examples are specific and complete. | 3 / 3 |
Workflow Clarity | The quick start and development workflow sections provide clear sequences, but the iterative development workflow lacks validation checkpoints—there's no mention of verifying the build succeeded before registering, no error recovery guidance if plugin registration fails, and no validation step after changes. For a workflow involving build/install/register cycles, explicit validation would strengthen this. | 2 / 3 |
Progressive Disclosure | Excellent structure with a concise overview and quick start at the top, inline essentials for common patterns, and clear one-level-deep references to advanced-features.md, examples.md, testing-debugging.md, and plugin-protocol.md. The reference documentation section is well-organized with descriptive labels for each file. | 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.
- Repository
- YPares/agent-skills
- Commit
aed1afb
- Reviewed
Table of Contents
Is this your skill?
If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.