Execute a read-only SQL SELECT query against the connected 3DCityDB database
AI agents invoke run_query to trigger actions in 3DCityDB MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
Although the tool is restricted to SELECT queries (read-only), it still executes arbitrary SQL code provided by the AI agent. An agent could craft malicious or resource-exhausting queries (e.g., expensive JOINs, cartesian products) that trigger denial-of-service, information disclosure through side-channel analysis, or exhaust database resources.
From the tool's definition Tool explicitly named 'run_query' with description 'Execute a read-only SQL SELECT query against the connected 3DCityDB database'. The verb 'Execute' and ability to run arbitrary SQL queries qualifies it as Execute category despite read-only constraints.
Documented attack patterns abuse exactly the kind of access run_query gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and 3DCityDB MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for run_query:
{
"version": "1",
"default": "deny",
"tools": {
"run_query": {
"limits": [
{
"counter": "run_query_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}run_query stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Execute a read-only SQL SELECT query against the connected 3DCityDB database. It is categorised as a Execute tool in the 3DCityDB MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the 3DCityDB MCP Server MCP server in PolicyLayer and add a rule for run_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 3DCityDB MCP Server. Nothing to install.
run_query is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the run_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 run_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.
run_query is provided by the 3DCityDB MCP Server MCP server (tum-gis/3dcitydb-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from 3DCityDB 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.
14 3DCityDB MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.