Universal Database MCP Server

Explain

explain

Analyze SQL query performance by retrieving the execution plan without executing the query. Identify bottlenecks and optimize queries safely.

Instructions

Get query execution plan without running the query.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "sql": "<sql>"
    },
    "name": "explain"
  }
}

Input Schema

Name	Required	Description
`sql`	Yes	SQL query to analyze
`params`	No	Optional parameters for the query
`database`	No	Database key (format: "type:name")

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.1.3Sep 8, 2026

TDQS

A4.2/5.0

Behavior4/5

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

With no annotations provided, the description carries the burden of explaining side effects, and it does so by stating the query is not run. This is the most important behavioral detail, though it does not elaborate on other potential behaviors such as needing a live database connection.

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

Conciseness5/5

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

The description is a single, focused sentence with no wasted words. It front-loads the core purpose and immediately clarifies the key non-execution behavior.

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

Completeness4/5

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

Given the output schema exists, the description does not need to explain return values. It covers the main purpose, the critical behavioral constraint, and is supported by schema-level parameter details. It could be slightly more explicit about how this relates to the query sibling tool, but it is still reasonably complete.

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

Parameters3/5

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 schema descriptions add moderate value: 'sql' is tied to analysis, 'params' is generic, and 'database' provides a useful format hint. None of the parameter descriptions are deeply enriched beyond the schema.

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?

The description uses a specific verb ('Get') and a clear resource ('query execution plan'), and explicitly notes it does not run the query. This distinguishes it well from sibling tools like query, which actually executes queries.

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

Usage Guidelines4/5

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

The phrase 'without running the query' gives clear guidance that this is for plan inspection rather than execution. It does not explicitly name alternatives like query, but the intent is still clear enough for an agent to choose appropriately.

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

Deploy Server