db-query-mcp

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query

Execute read-only SELECT, WITH, PRAGMA, or EXPLAIN statements on SQLite databases; returns columns, rows, row count, and truncation status.

Instructions

执行只读 SQL 查询(SELECT/WITH/PRAGMA/EXPLAIN)。返回 {columns, rows, row_count, truncated}。结果默认最多 500 行。

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": {
      "db_path": "<db_path>",
      "sql": "<sql>"
    },
    "name": "query"
  }
}

Input Schema

Name	Required	Description	Default
`sql`	Yes
`db_path`	Yes
`max_rows`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 16, 2026

TDQS

B3.3/5.0

Behavior3/5

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

With no annotations, the description carries the full burden and does disclose useful traits: read-only enforcement, the permitted statement classes, and result truncation. However it omits error/permission behavior, and its claim of a 500-row default directly conflicts with the schema's max_rows default of 200, which undermines confidence in the stated limits.

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?

Three compact sentences with no filler; the purpose leads, followed by return shape and the row cap. Every clause adds information an agent can act on.

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

Completeness3/5

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

An output schema exists, so the description need not explain return values, yet it spends a sentence doing so. Combined with the unaddressed db_path parameter and the conflicting row-limit figure, the definition is adequate for a simple query tool but leaves gaps an agent would have to guess at.

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

Parameters2/5

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

Schema description coverage is 0%, so the description must compensate for all three parameters (sql, db_path, max_rows). It says nothing about what db_path should contain or the SQL dialect/constraints, and its only parameter-adjacent claim (500-row default) contradicts the schema default of 200.

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

Purpose4/5

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

States a specific verb and resource ('执行只读 SQL 查询') and narrows scope with an explicit statement whitelist (SELECT/WITH/PRAGMA/EXPLAIN), which is enough to separate it from the sibling schema tool. It stops short of explicitly naming the alternative, but the operation is unambiguous.

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

Usage Guidelines3/5

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

The allowed statement types imply when the tool applies (read-only data retrieval) and implicitly exclude writes, but there is no explicit when-to-use, when-not-to-use, or routing against the sibling 'schema' tool. Usage is inferable rather than stated.

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

Deploy Server

Other Tools

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