clickhouse-migrations

ClickHouse migration patterns and rules. Use when creating or modifying ClickHouse migrations.

Quality

83%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide

Securityby

Passed

No findings from the security scan

Quality

Content

87%Weight 40%Scale 1-5

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

A high-signal, domain-specific reference that is lean and highly actionable with one clearly signaled external pointer. The one weakness is workflow clarity: destructive migration operations are governed by rules but lack an explicit validation/retry feedback loop, which the rubric caps at 3.

Suggestions

Add a short ordered migration workflow (write migration -> run locally -> verify table created in local dev -> check cloud guard parity) with explicit validation checkpoints before shipping.

Include a validate-and-retry loop for the destructive cases, e.g. after DROP TABLE IF EXISTS ... SYNC, verify the table is gone before recreating, and how to recover if the drop stalls.

Surface a brief verification step for the testing section beyond the single re-run hint (e.g. how to confirm a migration applied cleanly in local dev).

Dimension	Reasoning	Score
Conciseness	The body is a dense reference with no padding of concepts Claude already knows; explanatory prose (CODEC ordering, DROP COLUMN two-step, kafka no-go zone) covers genuinely non-obvious ClickHouse internals where every token earns its place. Not a 4 because there is no trimmable over-explanation.	5 / 5
Actionability	Provides copy-paste-ready operation scaffolding, exact node-role lists, concrete engine signatures, and the specific schema.py tuples to edit; specific examples cover the common sharded/replicated/ingestion cases. Not a 4 because guidance is executable rather than leaving gaps.	5 / 5
Workflow Clarity	Content is rule/reference style rather than a sequenced multi-step workflow, and the destructive/batch operations (DROP COLUMN, DROP TABLE SYNC, schema migrations) lack an explicit validate-then-fix-then-retry feedback loop; per the rubric's destructive-operation cap, workflow clarity is capped at 3.	3 / 5
Progressive Disclosure	The top line delegates the deep reference to posthog/clickhouse/migrations/AGENTS.md as a clearly signaled one-level-deep pointer, while the body keeps a well-organized quick reference; no bundle files exist to over-nest, matching the well-organized single-file anchor.	5 / 5
	Total	18 / 20 Passed

Description

78%Weight 40%Scale 1-5

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

A concise, well-targeted description that states both capability and trigger, scoped tightly to ClickHouse migrations with low conflict risk. The main gap is the slightly abstract 'what' phrasing and limited trigger-term variety.

Suggestions

Expand the 'what' with one or two concrete actions (e.g. 'Add, alter, or drop ClickHouse tables via run_sql_with_exceptions operations') to lift specificity.

Broaden trigger terms with synonyms users say, such as '.sql migration', 'schema change', or 'ALTER TABLE on ClickHouse'.

Consider listing the key scenarios (sharded vs replicated tables, ingestion-layer tables) in the description to sharpen the trigger.

Dimension	Reasoning	Score
Specificity	Quotes 'ClickHouse migration patterns and rules' and 'creating or modifying ClickHouse migrations' name the domain plus two concrete actions; not a 5 because 'patterns and rules' is somewhat abstract rather than a comprehensive list of specific actions.	4 / 5
Completeness	Both 'what' (patterns and rules) and an explicit 'when' ('Use when creating or modifying ClickHouse migrations') are present; held below 5 because the 'what' is terse and the trigger phrase set is narrow.	4 / 5
Trigger Term Quality	Natural terms 'ClickHouse', 'migrations', and 'creating or modifying' are present; a 5 would require synonyms/extensions like '.sql', 'schema change', or 'ALTER TABLE' which are missing.	4 / 5
Distinctiveness Conflict Risk	'ClickHouse migrations' is a clear, narrow niche with distinct triggers and minimal overlap risk with other skills; matches the anchor for a clear niche.	5 / 5
	Total	17 / 20 Passed

Validation

100%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository: PostHog/posthog
Path: .agents/skills/clickhouse-migrations/SKILL.md
Commit: 6fca5f8

Reviewed: 3 days ago

Table of Contents

Discovery Implementation Validation

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.