Point-in-polygon and geometric containment queries (requires PostGIS)
AI agents call geo_within to retrieve information from Postgres Mcp Legacy without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool executes queries against a PostGIS-enabled PostgreSQL database to determine if geographic points fall within polygon boundaries. This is a pure read operation with no side effects: it does not create, modify, delete, or execute arbitrary code. The blast radius of misuse is minimal—an attacker could only extract or infer information about geometric relationships in the database.
From the tool's definition Tool description explicitly states it performs 'Point-in-polygon and geometric containment queries'—these are read-only spatial operations that retrieve geometric relationships without modifying data.
Documented attack patterns abuse exactly the kind of access geo_within gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Postgres Mcp Legacy, and nothing reaches the server without passing your rules. This is the rule we recommend for geo_within:
{
"version": "1",
"default": "deny",
"tools": {
"geo_within": {}
}
}geo_within 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.
Point-in-polygon and geometric containment queries (requires PostGIS). It is categorised as a Read tool in the Postgres Mcp Legacy MCP Server, which means it retrieves data without modifying state.
Register the Postgres Mcp Legacy MCP server in PolicyLayer and add a rule for geo_within: 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 Postgres Mcp Legacy. Nothing to install.
geo_within 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 geo_within 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 geo_within. 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.
geo_within is provided by the Postgres Mcp Legacy MCP server (neverinfamous/postgres-mcp-legacy). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Postgres Mcp Legacy, 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.
60 Postgres Mcp Legacy tools catalogued and risk-classified — across an index of 43,000+ MCP servers.