mongo-aggregate · MCP Server Boilerplate MCP: Risk & Policy

WHAT IT DOES

What mongo-aggregate does on MCP Server Boilerplate

AI agents invoke mongo-aggregate to trigger actions in MCP Server Boilerplate. 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 mongo-aggregate needs a policy

This tool executes arbitrary operations on a MongoDB collection via aggregation pipelines. While the default behavior may be read-only queries, aggregation pipelines support stages like $out and $merge that can write data, and the tool's flexibility makes it Execute rather than Read.

From the tool's definition Tool is described as 'Execute aggregation pipeline on a MongoDB collection'. The verb 'execute' combined with 'aggregation pipeline' indicates the tool runs operations whose effects depend on the pipeline arguments provided.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mongo-aggregate Rate-limited

mongo-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": {
    "mongo-aggregate": {
      "limits": [
        {
          "counter": "mongo-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 MCP Server Boilerplate, so you can run agents against it safely.

FAQ

Questions about mongo-aggregate

What does the mongo-aggregate tool do? +

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

How do I enforce a policy on mongo-aggregate? +

Register the MCP Server Boilerplate MCP server in PolicyLayer and add a rule for mongo-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 MCP Server Boilerplate. Nothing to install.

What risk level is mongo-aggregate? +

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

Can I rate-limit mongo-aggregate? +

Yes. Add a rate_limit block to the mongo-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 mongo-aggregate completely? +

Set action: deny in the PolicyLayer policy for mongo-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 mongo-aggregate? +

mongo-aggregate is provided by the MCP Server Boilerplate MCP server (ricleedo/mongo-boilerplate-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.