datastore_update · MCP Datastore Server MCP: Risk & Policy

WHAT IT DOES

What datastore_update does on MCP Datastore Server

AI agents use datastore_update to create or update resources in MCP Datastore Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP Datastore Server environment.

WHY IT NEEDS A POLICY

Why datastore_update needs a policy

This tool modifies existing data in Firestore/Datastore in a reversible manner (updates can be undone via subsequent updates or transactions). It is not destructive (no deletion), not financial, and not execute-level arbitrary code. However, severity is high because unauthorized updates to a production database could corrupt critical business data, affect system integrity, and impact multiple users.

From the tool's definition Tool name 'datastore_update' and description 'Update an existing entity in Datastore' indicate modification of data. The verb 'update' and the context of sibling CRUD operations confirm write functionality.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

datastore_update Rate-limited

datastore_update stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "datastore_update": {
      "limits": [
        {
          "counter": "datastore_update_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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 Datastore Server, so you can run agents against it safely.

FAQ

Questions about datastore_update

What does the datastore_update tool do? +

Update an existing entity in Datastore. It is categorised as a Write tool in the MCP Datastore Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on datastore_update? +

Register the MCP Datastore Server MCP server in PolicyLayer and add a rule for datastore_update: 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 Datastore Server. Nothing to install.

What risk level is datastore_update? +

datastore_update is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit datastore_update? +

Yes. Add a rate_limit block to the datastore_update 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 datastore_update completely? +

Set action: deny in the PolicyLayer policy for datastore_update. 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 datastore_update? +

datastore_update is provided by the MCP Datastore Server MCP server (petekmet/mcp-gcp-datastore). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.