Execute a read-only SQL query (SELECT, SHOW, DESCRIBE, EXPLAIN, WITH statements only)
AI agents call execute_query to retrieve information from PostgreSQL MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool is explicitly restricted to read-only SQL statements (SELECT, SHOW, DESCRIBE, EXPLAIN, WITH), meaning it retrieves data without side effects. However, severity is medium because enforcement of the read-only constraint depends on implementation — if the restriction is only advisory and not enforced at the database level (e.g., via a read-only role or transaction), a malicious or erroneous query could bypass…
From the tool's definition 'Execute a read-only SQL query (SELECT, SHOW, DESCRIBE, EXPLAIN, WITH statements only)' and server description states 'secure read-only access'
Attacks that exploit this kind of access
Execute a read-only SQL query (SELECT, SHOW, DESCRIBE, EXPLAIN, WITH statements only). It is categorised as a Read tool in the PostgreSQL MCP Server MCP Server, which means it retrieves data without modifying state.
Register the PostgreSQL MCP Server MCP server in PolicyLayer and add a rule for execute_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 PostgreSQL MCP Server. Nothing to install.
execute_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 execute_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 execute_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.
execute_query is provided by the PostgreSQL MCP Server MCP server (melihbirim/pg-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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