database-sharding
Database sharding for PostgreSQL/MySQL with hash/range/directory strategies. Use for horizontal scaling, multi-tenant isolation, billions of records, or encountering wrong shard keys, hotspots, cross-shard transactions, rebalancing issues.
Install with Tessl CLI
npx tessl i github:secondsky/claude-skills --skill database-sharding93
Does it follow best practices?
Agent success when using this skill
Validation for skill structure
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 an excellent skill description that clearly defines its scope (database sharding), supported technologies (PostgreSQL/MySQL), specific strategies (hash/range/directory), and explicit trigger conditions covering both proactive use cases (horizontal scaling, multi-tenant) and reactive troubleshooting scenarios (hotspots, rebalancing issues). The description uses proper third-person voice and provides comprehensive trigger terms that database engineers would naturally use.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions and concepts: 'Database sharding', 'hash/range/directory strategies', 'horizontal scaling', 'multi-tenant isolation', 'billions of records', and specific issues like 'wrong shard keys, hotspots, cross-shard transactions, rebalancing issues'. | 3 / 3 |
Completeness | Clearly answers both what ('Database sharding for PostgreSQL/MySQL with hash/range/directory strategies') and when ('Use for horizontal scaling, multi-tenant isolation, billions of records, or encountering wrong shard keys, hotspots, cross-shard transactions, rebalancing issues'). | 3 / 3 |
Trigger Term Quality | Excellent coverage of natural terms users would say: 'sharding', 'PostgreSQL', 'MySQL', 'horizontal scaling', 'multi-tenant', 'hotspots', 'cross-shard transactions', 'rebalancing'. These are terms database engineers naturally use when facing scaling challenges. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive with clear niche focus on database sharding specifically for PostgreSQL/MySQL. The specific strategies (hash/range/directory) and problem domains (hotspots, cross-shard transactions) make it unlikely to conflict with general database or scaling skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
85%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, well-structured skill with excellent actionability and progressive disclosure. The code examples are executable and the workflow guidance is clear with proper validation steps. The main weakness is some redundancy between sections (error catalog appears twice) and overall length that could be trimmed without losing value.
Suggestions
Consolidate the 'Top 7 Critical Errors' and 'Known Issues Prevention' sections to eliminate redundancy - keep the detailed fixes in one place and reference them from the other
Trim the production example to show just the 'after' pattern with brief metrics, since Claude understands the 'before' problem from context
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is reasonably efficient but includes some redundancy - the error catalog is summarized twice (in Top 7 Critical Errors and Known Issues Prevention sections), and some explanations like the production example could be tighter. The tables and checklists are well-structured but the overall document is verbose at ~400 lines. | 2 / 3 |
Actionability | Excellent actionability with fully executable TypeScript code examples, specific SQL queries showing both bad and good patterns, concrete configuration examples, and copy-paste ready router implementations. The before/after production example with specific metrics is particularly strong. | 3 / 3 |
Workflow Clarity | Clear multi-step workflows with explicit validation checkpoints. The Quick Start provides numbered steps, the Complete Setup Checklist has verification checkboxes, and error patterns include symptom → fix sequences. The 'When to Load References' section provides clear decision points. | 3 / 3 |
Progressive Disclosure | Excellent progressive disclosure with a clear Quick Start, well-organized sections, and consistent one-level-deep references to detailed materials (references/*.md, templates/*.ts). The 'When to Load References' section explicitly guides when to access deeper content. | 3 / 3 |
Total | 11 / 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.
Validation — 10 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
Total | 10 / 11 Passed | |
- Reviewed
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