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tdg-personal/clickhouse-io

ClickHouse database patterns, query optimization, analytics, and data engineering best practices for high-performance analytical workloads.

39

Quality

49%

Does it follow best practices?

Impact

No eval scenarios have been run

SecuritybySnyk

Passed

No known issues

Overview
Quality
Evals
Security
Files

Quality

Content

42%

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

The skill provides highly actionable, executable code examples covering a broad range of ClickHouse patterns, which is its primary strength. However, it is excessively verbose — much of the content (overview, key features, general analytics query patterns) is knowledge Claude already possesses. The monolithic structure with no progressive disclosure and missing validation steps in workflows significantly reduce its effectiveness as a skill file.

Suggestions

Remove the Overview section and 'Key Features' list entirely — Claude knows what ClickHouse is. Cut the 'When to Activate' section as well.

Split into multiple files: keep SKILL.md as a concise overview with table design and core optimization patterns, then reference separate files like ANALYTICS_QUERIES.md, DATA_PIPELINES.md, and MONITORING.md.

Add validation checkpoints to the data insertion and ETL workflows — e.g., verify row counts after bulk insert, check for errors in the query log, validate schema before migration.

Remove generic analytics query patterns (funnel, cohort, retention) that are standard SQL knowledge, or condense them to a brief reference table of ClickHouse-specific functions used in each pattern.

DimensionReasoningScore

Conciseness

The skill is extremely verbose at ~400+ lines. It explains what ClickHouse is ('column-oriented DBMS for OLAP'), lists key features Claude already knows, includes an unnecessary 'When to Activate' section, and provides extensive example queries for common analytics patterns (funnel, cohort, retention) that are general SQL knowledge. The overview section and best practices bullet points largely restate things Claude would already know.

1 / 3

Actionability

The skill provides fully executable SQL and TypeScript code examples throughout — CREATE TABLE statements, query patterns with concrete column names, bulk insert implementations, materialized view definitions, and monitoring queries against system tables. All examples are copy-paste ready with realistic schemas.

3 / 3

Workflow Clarity

The ETL pipeline section shows a clear sequence (extract → transform → load), and table design flows logically from engine selection to materialized views. However, there are no validation checkpoints — no steps to verify data was inserted correctly, no error handling in the bulk insert (which is a batch/destructive operation), and no feedback loops for schema migration or data pipeline failures.

2 / 3

Progressive Disclosure

This is a monolithic wall of text with no references to external files. All content — table design, query optimization, insertion patterns, materialized views, monitoring, analytics queries, pipeline patterns, and best practices — is inlined in a single massive document. Content like common analytics queries, CDC patterns, and ETL examples could easily be split into separate referenced files.

1 / 3

Total

7

/

12

Passed

Description

32%

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description identifies ClickHouse as the target domain and mentions broad capability areas, but it reads more like a topic label than an actionable skill description. It lacks specific concrete actions, explicit trigger conditions ('Use when...'), and sufficient natural keyword variations to reliably distinguish it from other database or analytics skills.

Suggestions

Add an explicit 'Use when...' clause, e.g., 'Use when the user asks about ClickHouse queries, schema design, MergeTree engines, or analytical database performance.'

List specific concrete actions such as 'Designs MergeTree table schemas, writes optimized analytical queries, configures materialized views, troubleshoots query performance.'

Include natural trigger term variations like 'OLAP', 'columnar database', 'MergeTree', 'ReplacingMergeTree', 'distributed tables', and 'CH' to improve matching coverage.

DimensionReasoningScore

Specificity

Names the domain (ClickHouse database) and some general action areas (query optimization, analytics, data engineering best practices), but doesn't list specific concrete actions like 'write MergeTree table definitions' or 'optimize GROUP BY queries'.

2 / 3

Completeness

Describes what the skill covers at a high level but completely lacks a 'Use when...' clause or any explicit trigger guidance for when Claude should select this skill. Per rubric guidelines, a missing 'Use when...' clause caps completeness at 2, and the 'what' is also fairly weak, so this scores a 1.

1 / 3

Trigger Term Quality

Includes relevant keywords like 'ClickHouse', 'query optimization', 'analytics', and 'data engineering', which users might naturally say. However, it misses common variations like 'columnar database', 'OLAP', 'MergeTree', 'materialized views', or '.clickhouse' that would improve matching.

2 / 3

Distinctiveness Conflict Risk

'ClickHouse' is a distinct technology that provides good differentiation, but terms like 'query optimization', 'analytics', and 'data engineering best practices' are generic enough to overlap with skills for other databases (e.g., PostgreSQL, BigQuery, Snowflake).

2 / 3

Total

7

/

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.

Validation10 / 11 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

10

/

11

Passed

Reviewed

Table of Contents