mongodb_aggregate · Multi-Database MCP Server MCP

WHAT IT DOES

What mongodb_aggregate does on Multi-Database MCP Server

AI agents invoke mongodb_aggregate to trigger actions in Multi-Database 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.

WHY IT NEEDS A POLICY

Why mongodb_aggregate needs a policy

Although aggregation pipelines are often used for read-only queries, MongoDB's aggregation framework supports stages like $out, $merge, and $function that can write data, execute arbitrary code, or have side effects beyond simple data retrieval. The tool's capability depends heavily on the pipeline stages provided as arguments.

From the tool's definition "Run an aggregation pipeline on a MongoDB collection" - aggregation pipelines execute complex multi-stage operations that can modify data flow, compute results, and trigger side effects depending on pipeline stage arguments (e.g., $out, $merge stages can…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mongodb_aggregate Rate-limited

mongodb_aggregate 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "mongodb_aggregate": {
      "limits": [
        {
          "counter": "mongodb_aggregate_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Multi-Database MCP Server, so you can run agents against it safely.

FAQ

Questions about mongodb_aggregate

What does the mongodb_aggregate tool do? +

Run an aggregation pipeline on a MongoDB collection. It is categorised as a Execute tool in the Multi-Database MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on mongodb_aggregate? +

Register the Multi-Database MCP Server MCP server in PolicyLayer and add a rule for mongodb_aggregate: 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 Multi-Database MCP Server. Nothing to install.

What risk level is mongodb_aggregate? +

mongodb_aggregate is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit mongodb_aggregate? +

Yes. Add a rate_limit block to the mongodb_aggregate 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.

How do I block mongodb_aggregate completely? +

Set action: deny in the PolicyLayer policy for mongodb_aggregate. 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.

What MCP server provides mongodb_aggregate? +

mongodb_aggregate is provided by the Multi-Database MCP Server MCP server (nam088/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.