Execute a SELECT query to read data from the database
AI agents call read_query to retrieve information from MSSQL MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs read-only operations on the database. SELECT queries are non-destructive retrieval operations that do not modify, create, or delete any data. Even though the server provides access to destructive operations (delete_index, delete_procedure, delete_view), this specific tool is limited to data retrieval.
From the tool's definition Tool name is 'read_query' and description explicitly states 'Execute a SELECT query to read data from the database'. SELECT queries retrieve data without side effects or modifications.
Documented attack patterns abuse exactly the kind of access read_query gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MSSQL MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for read_query:
{
"version": "1",
"default": "deny",
"tools": {
"read_query": {}
}
}read_query is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Execute a SELECT query to read data from the database. It is categorised as a Read tool in the MSSQL MCP Server MCP Server, which means it retrieves data without modifying state.
Register the MSSQL MCP Server MCP server in PolicyLayer and add a rule for read_query: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches MSSQL MCP Server. Nothing to install.
read_query is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the read_query rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for read_query. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
read_query is provided by the MSSQL MCP Server MCP server (jensenloke/mcp-sqlserver-pro). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MSSQL MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
23 MSSQL MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.