Diogenes Database Intelligence, SQL Engine & Schema Guard MCP

Relational Schema Normalization Auditor (3NF, BCNF) & Integrity Guard

validate_schema_normalization

Read-onlyIdempotent

Audit database schemas for 3NF compliance, transitive dependencies, and missing foreign keys to prevent update anomalies and validate relational integrity.

Instructions

Audits database schemas for third normal form (3NF) compliance, transitive dependencies, and missing foreign key constraints. Use when reviewing database architectures, preventing update anomalies, or validating relational integrity; for detecting breaking schema migrations, use detect_breaking_migrations instead. Stateless read-only edge call (max 32 KB, 60 RPM): accepts 'schema_ddl' ('target_normal_form' defaults to 'third_normal_form_3nf'), supports '?demo=true' or L402 (10 sats), and returns HTTP 400 if invalid.

Input Schema

Name	Required	Description
`schema_ddl`	Yes	Database schema DDL statements defining table columns, primary keys, and relations.
`strict_keys`	No	Whether to enforce explicit foreign key constraints on all ID references.
`target_normal_form`	No	Target normalization standard: 3NF, Boyce-Codd BCNF, or denormalized OLAP star.

Output Schema

Name	Required	Description
`conforms_to_target`	Yes	True if the schema strictly satisfies the chosen normal form requirements.
`normalization_score`	Yes	Schema relational design quality score on a 0 to 100 scale.
`redundancies_flagged`	Yes	List of redundant fields, missing primary keys, or transitive dependencies identified.
`refactoring_suggestions`	Yes	Specific table decomposition and foreign key recommendations to achieve compliance.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 26, 2026

TDQS

A4.8/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), and the description goes beyond them with statelessness, a 32 KB payload cap, 60 RPM rate limit, demo mode or L402 payment of 10 sats, and HTTP 400 on invalid input. These are operational facts an agent cannot obtain from the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose and the sibling alternative before the operational constraints, with no filler sentences. It is dense to the point of being one long sentence with stacked parentheticals, which slightly hurts scanability.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need no explanation, and the annotations carry the safety profile. What remains — payload limits, rate limit, payment path, error behavior, and the parameter default — is all covered, leaving nothing an agent needs to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3; the description adds genuine value by disclosing that target_normal_form defaults to 'third_normal_form_3nf', a default the schema does not state. It adds little else about strict_keys, keeping it below a 5.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource set: audits schemas for 3NF compliance, transitive dependencies, and missing foreign key constraints. It also explicitly names the sibling it is not (detect_breaking_migrations), so an agent can distinguish it without opening either schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives concrete use cases (reviewing database architectures, preventing update anomalies, validating relational integrity) and an explicit exclusion routing to detect_breaking_migrations for migration breakage. Both the when and the when-not are present.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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