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alonso-skills/sql-server-performance

Diagnoses and optimizes SQL Server database performance. Use when diagnosing slow T-SQL queries, tuning indexes, reading execution plans, fixing parameter sniffing, optimizing batch operations, reducing transaction log bloat, troubleshooting locking and blocking, configuring tempdb, or when a query that used to be fast is now slow. Also use when writing high-throughput INSERT/UPDATE/DELETE operations, implementing minimal logging, designing covering indexes, or analyzing wait statistics.

80

Quality

100%

Does it follow best practices?

Impact

No eval scenarios have been run

SecuritybySnyk

Passed

No known issues

Overview
Quality
Evals
Security
Files

Quality

Content

100%

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

This is an exceptionally well-crafted skill that serves as a model for SQL Server performance tuning guidance. It combines a structured diagnostic workflow with concrete, executable code examples and clear decision frameworks (temp tables vs table variables, parameter sniffing strategies ranked by preference). The progressive disclosure is excellent, keeping the main file focused on the diagnostic process and core patterns while pointing to detailed reference files for deeper dives.

DimensionReasoningScore

Conciseness

The content is dense with actionable information and avoids explaining concepts Claude already knows. Every section delivers specific SQL, concrete thresholds, or decision rules without padding. Comments in code are minimal and purposeful.

3 / 3

Actionability

Fully executable T-SQL throughout — wait stats delta queries, missing index DMVs, covering index CREATE statements, parameter sniffing fixes with complete stored procedure examples. The SARGability table provides exact before/after rewrites. Everything is copy-paste ready.

3 / 3

Workflow Clarity

The diagnostic flowchart is a clear 5-step sequence where each step narrows the cause before proceeding. Each step includes what to look for and what to do if the symptom is found, creating implicit feedback loops (e.g., 'fix statistics so the grant is sized correctly' then re-evaluate). The ranked parameter sniffing strategies provide explicit ordering.

3 / 3

Progressive Disclosure

The SKILL.md provides a comprehensive but focused overview with well-signaled one-level-deep references to six specific reference files (execution-plans.md, index-strategy.md, wait-stats.md, locking-blocking.md, batch-operations.md, statistics-tuning.md). References are contextually placed where relevant and also collected in a final Reference Files section for discovery.

3 / 3

Total

12

/

12

Passed

Description

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 hits all the marks. It provides a concise high-level summary followed by an extensive and well-organized 'Use when' clause with highly specific, natural trigger terms that a SQL Server DBA or developer would actually use. The description is distinctive, uses proper third-person voice, and covers both the 'what' and 'when' comprehensively.

DimensionReasoningScore

Specificity

Lists multiple specific concrete actions: diagnosing slow T-SQL queries, tuning indexes, reading execution plans, fixing parameter sniffing, optimizing batch operations, reducing transaction log bloat, troubleshooting locking and blocking, configuring tempdb, implementing minimal logging, designing covering indexes, and analyzing wait statistics.

3 / 3

Completeness

Clearly answers both 'what' (diagnoses and optimizes SQL Server database performance) and 'when' with an explicit 'Use when...' clause listing numerous specific trigger scenarios. The 'when' section is comprehensive and well-structured.

3 / 3

Trigger Term Quality

Excellent coverage of natural terms users would say: 'slow T-SQL queries', 'execution plans', 'parameter sniffing', 'locking and blocking', 'tempdb', 'transaction log bloat', 'wait statistics', 'covering indexes', 'query that used to be fast is now slow'. These are exactly the phrases a DBA or developer would use when seeking help.

3 / 3

Distinctiveness Conflict Risk

Highly distinctive with a clear niche: SQL Server-specific performance tuning. Terms like 'T-SQL', 'tempdb', 'parameter sniffing', and 'wait statistics' are uniquely SQL Server concepts, making it very unlikely to conflict with general database or other RDBMS skills.

3 / 3

Total

12

/

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.

Validation11 / 11 Passed

Validation for skill structure

No warnings or errors.

Reviewed

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