SQL Server MCP Server

read_query

Execute a read-only SELECT query against a SQL Server database. Pass positional parameter values to run custom data retrievals without modifying records.

Instructions

Execute a custom read-only SELECT query against the SQL Server database.

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_query": "<sql_query>"
    },
    "name": "read_query"
  }
}

Input Schema

Name	Required	Description	Default
`params`	No	List of positional parameter values for query placeholders (?).
`sql_query`	Yes	T-SQL SELECT query (e.g., "SELECT u.id, u.name, o.total FROM dbo.users u JOIN dbo.orders o ON u.id = o.user_id WHERE u.active = ?").

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 19, 2026

TDQS

A3.9/5.0

Behavior3/5

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

Since no annotations are provided, the description must disclose behavioral traits. It mentions 'read-only', which is a key safety property. However, it does not elaborate on permission requirements, result size limits, or error behavior, leaving the agent with only the bare minimum. It covers the core but is not rich.

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 concise sentence that front-loads the core purpose. No wasted words; every term is meaningful. It achieves maximum clarity in minimal length.

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?

With an output schema available, return values are covered elsewhere. The description adequately covers the read-only nature and custom SELECT scope. However, it does not clarify when to prefer this over execute_sql, which is a significant sibling overlap, leaving a small gap in contextual completeness.

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 schema already documents both parameters (sql_query and params) with examples and types. The description adds no additional parameter-level details, so the baseline score of 3 applies.

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 clearly states the action (execute), the resource (SQL Server database), and the scope (custom read-only SELECT query). This distinguishes it from siblings like read_records (structured reads) and execute_sql (potentially non-SELECT operations).

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 description provides clear context by specifying a custom read-only SELECT query, implying this is for ad-hoc reads not covered by structured tools like read_records. However, it does not explicitly state when not to use it or contrast with execute_sql, so it's clear but lacks exclusions/alternatives.

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

Deploy Server