kotlin-specialist
Use when building Kotlin applications requiring coroutines, multiplatform development, or Android with Compose. Invoke for Flow API, KMP projects, Ktor servers, DSL design, sealed classes.
Install with Tessl CLI
npx tessl i github:jeffallan/claude-skills --skill kotlin-specialistOverall
score
61%
Does it follow best practices?
If you maintain this skill, you can automatically optimize it using the tessl CLI to improve its score:
npx tessl skill review --optimize ./path/to/skillValidation for skill structure
Discovery
72%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 description excels at trigger terms and distinctiveness with comprehensive Kotlin ecosystem keywords, making it easy to identify when needed. However, it lacks specificity about what actions or capabilities the skill provides - it tells Claude when to use it but not what it actually does beyond 'building applications'.
Suggestions
Add concrete actions describing what the skill does, e.g., 'Guides architecture patterns, implements coroutine scopes, configures Gradle multiplatform builds'
Replace the vague 'building Kotlin applications' with specific capabilities like 'structure suspend functions, design state flows, create platform-specific implementations'
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (Kotlin) and lists several specific technologies (coroutines, multiplatform, Compose, Flow API, KMP, Ktor, DSL, sealed classes), but doesn't describe concrete actions - only mentions 'building' without specifying what actions the skill performs. | 2 / 3 |
Completeness | Has explicit 'Use when' and 'Invoke for' clauses addressing when to use it, but the 'what does this do' is weak - it only says 'building applications' without describing specific capabilities or actions the skill provides. | 2 / 3 |
Trigger Term Quality | Excellent coverage of natural terms users would say: 'Kotlin', 'coroutines', 'multiplatform', 'Android', 'Compose', 'Flow API', 'KMP', 'Ktor', 'DSL', 'sealed classes' - these are all terms developers naturally use when working in this domain. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive with Kotlin-specific terminology (KMP, Ktor, sealed classes, Flow API, Compose) that clearly separates it from general programming skills or other language-specific skills. | 3 / 3 |
Total | 10 / 12 Passed |
Implementation
42%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
The skill has strong progressive disclosure with a well-organized reference table, but critically lacks actionable code examples. The content reads more like a role description than executable guidance - it tells Claude what patterns to use without showing how. The constraints are useful but would benefit from concrete examples of correct vs incorrect code.
Suggestions
Add executable code examples for key patterns: a coroutine/Flow example, a sealed class state modeling example, and a DSL builder example
Replace the abstract 'Role Definition' paragraph with a concrete quick-start code snippet demonstrating idiomatic Kotlin
Add validation checkpoints to the Core Workflow, especially for steps 3-4 (e.g., 'Run detekt/ktlint before committing', 'Verify coroutine tests pass with runTest')
Convert MUST DO/MUST NOT DO items into concrete before/after code examples showing the correct pattern
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill includes some unnecessary framing ('You are a senior Kotlin engineer with 10+ years...') and the 'When to Use This Skill' section largely duplicates the description. The constraints and knowledge reference sections are reasonably efficient. | 2 / 3 |
Actionability | No executable code examples are provided. The content describes what to do abstractly ('Use sealed class for state modeling', 'Use Flow for reactive streams') but never shows concrete, copy-paste ready implementations. The workflow is high-level without specific commands or code. | 1 / 3 |
Workflow Clarity | The 5-step core workflow provides a sequence but lacks validation checkpoints or feedback loops. For a skill involving coroutines and multiplatform development where errors are common, there's no guidance on verification steps or error recovery. | 2 / 3 |
Progressive Disclosure | Excellent use of a reference table with clear topics, file paths, and 'Load When' conditions. The structure appropriately keeps the main skill as an overview while pointing to detailed references one level deep. | 3 / 3 |
Total | 8 / 12 Passed |
Validation
75%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 12 / 16 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
metadata_version | 'metadata' field is not a dictionary | Warning |
license_field | 'license' field is missing | Warning |
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
body_examples | No examples detected (no code fences and no 'Example' wording) | Warning |
Total | 12 / 16 Passed | |
- Reviewed
Table of Contents
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