rails-engine-author
Use when creating, scaffolding, or refactoring a Rails engine. Covers engine types (Plain, Railtie, Engine, Mountable), namespace isolation, host-app contract definition, and recommended file structure.
84
78%
Does it follow best practices?
Impact
91%
1.49xAverage score across 3 eval scenarios
Passed
No known issues
Optimize this skill with Tessl
npx tessl skill review --optimize ./rails-engine-author/SKILL.mdQuality
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 communicates both what the skill does and when to use it. It leads with an explicit 'Use when' clause containing natural trigger terms, enumerates specific capabilities, and occupies a distinct niche (Rails engines) that minimizes conflict risk with other skills.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions ('creating, scaffolding, or refactoring a Rails engine') and covers specific technical concepts (engine types with enumerated variants, namespace isolation, host-app contract definition, file structure). | 3 / 3 |
Completeness | Clearly answers both 'what' (covers engine types, namespace isolation, host-app contract definition, file structure) and 'when' (explicitly starts with 'Use when creating, scaffolding, or refactoring a Rails engine'). | 3 / 3 |
Trigger Term Quality | Includes strong natural trigger terms users would say: 'Rails engine', 'scaffolding', 'refactoring', 'mountable', 'Railtie', 'namespace isolation'. These are terms a developer would naturally use when needing this skill. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive niche focused specifically on Rails engines with specific subtopics (Railtie, Mountable, namespace isolation). Unlikely to conflict with general Rails skills or other framework skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
57%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 skill with good progressive disclosure and clear organization, but it suffers from some redundancy (engine type selection appears twice) and lacks the concrete, executable commands that would make it truly actionable. The workflow would benefit from explicit validation checkpoints, especially around verifying the engine mounts correctly in a dummy app.
Suggestions
Remove the 'Choose The Right Abstraction' section or merge it with the Quick Reference table to eliminate redundancy
Add concrete scaffold commands (e.g., `rails plugin new my_engine --mountable`) and a step-by-step creation sequence with executable shell commands
Add explicit validation checkpoints to the workflow, such as 'Run `bundle exec rake` in the dummy app to verify the engine loads' after step 3 and 'Mount the engine in the dummy app routes and verify with `rails routes`' after step 4
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is mostly efficient but has some redundancy — the 'Choose The Right Abstraction' section largely repeats the Quick Reference table, and some conventions (like namespace isolation) are stated multiple times across sections. The content could be tightened by ~20% without losing information. | 2 / 3 |
Actionability | The skill provides some concrete code examples (engine class, routes, configuration block) but the workflow and implementation rules are largely descriptive guidance rather than executable steps. Key operations like scaffolding the engine structure lack concrete commands (e.g., `rails plugin new my_engine --mountable`). | 2 / 3 |
Workflow Clarity | The workflow section lists 6 steps but they are high-level and lack validation checkpoints. For a task involving file structure creation and host-app integration, there are no explicit verification steps (e.g., 'run the dummy app tests to confirm mounting works') or error recovery guidance. | 2 / 3 |
Progressive Disclosure | The skill is well-organized with clear sections, a quick reference table up front, and appropriate references to adjacent skills and a reference.md file. Navigation is one level deep and clearly signaled through the Integration table and inline references. | 3 / 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
- igmarin/rails-agent-skills
- Commit
ae8ea63
- 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.