sql-query-mcp

start_query

Initiate an asynchronous read-only SELECT or CTE query on a database connection. Returns results while keeping the query running in the background.

Instructions

Start an asynchronous read-only SELECT or CTE 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": {
      "connection_id": "<connection_id>",
      "sql": "<sql>"
    },
    "name": "start_query"
  }
}

Input Schema

Name	Required	Description	Default
`sql`	Yes
`limit`	No
`connection_id`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Addedv0.3.0May 18, 2026

TDQS

B3.1/5.0

Behavior3/5

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

With no annotations, the description carries the burden. It discloses key behaviors: async (needs follow-up), read-only (no writes), and restricted to SELECT/CTE. However, it omits how to monitor or cancel queries, and does not mention authentication or rate 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?

Single sentence delivering essential information: verb, async, read-only, query type. No unnecessary words. Front-loaded with key differentiators.

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

Completeness2/5

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

Without output schema or parameter details, the description lacks completeness. It does not explain the full async flow (e.g., use get_query to retrieve results) or mention cancellation via cancel_query. For a tool initiating an async operation, this is insufficient.

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

Parameters1/5

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

Schema description coverage is 0%, yet the description says nothing about parameters. It does not explain sql format, connection_id purpose, or limit behavior. The description adds no meaning beyond the schema field names.

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 specifies 'Start an asynchronous read-only SELECT or CTE query.' This is a clear verb-resource pair with specific constraints (async, read-only, query type), distinguishing it from siblings like run_select (likely synchronous) and describe_table (describes schema).

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

Usage Guidelines2/5

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

The description provides no guidance on when to use this tool versus alternatives such as run_select or get_query. It does not explain the async nature implies subsequent polling or result retrieval. No exclusions or contexts are given.

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

Deploy Server