aggregate-documents · Universal Mcp Toolkit MCP

WHAT IT DOES

What aggregate-documents does on Universal Mcp Toolkit

AI agents invoke aggregate-documents to trigger actions in Universal Mcp Toolkit. 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 aggregate-documents needs a policy

This tool executes arbitrary MongoDB aggregation queries, whose side effects depend on the pipeline stages provided as arguments. Although write stages are reportedly disabled, executing aggregation pipelines (which can perform complex transformations, reads, and filtered operations) constitutes code/query execution.

From the tool's definition Run a MongoDB aggregation pipeline with write stages disabled by default." The tool executes a database aggregation pipeline, which is an arbitrary operation that can query and transform data based on arguments.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

aggregate-documents Rate-limited

aggregate-documents 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": {
    "aggregate-documents": {
      "limits": [
        {
          "counter": "aggregate-documents_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 Universal Mcp Toolkit, so you can run agents against it safely.

FAQ

Questions about aggregate-documents

What does the aggregate-documents tool do? +

Run a MongoDB aggregation pipeline with write stages disabled by default. It is categorised as a Execute tool in the Universal Mcp Toolkit MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

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

Register the Universal Mcp Toolkit MCP server in PolicyLayer and add a rule for aggregate-documents: 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 Universal Mcp Toolkit. Nothing to install.

What risk level is aggregate-documents? +

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

Can I rate-limit aggregate-documents? +

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

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

aggregate-documents is provided by the Universal Mcp Toolkit MCP server (markgatcha/universal-mcp-toolkit). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.