presign_image_batch · Rentalot MCP Server MCP: Risk & Policy

WHAT IT DOES

What presign_image_batch does on Rentalot MCP Server

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

WHY IT NEEDS A POLICY

Why presign_image_batch needs a policy

This tool facilitates creation/modification of data (property images) in a reversible manner. While it generates presigned URLs rather than directly storing images, it enables write operations by providing authenticated upload credentials. The moderate severity reflects potential for accidental image uploads or resource exhaustion, but images can typically be deleted.

From the tool's definition Described as 'Write operation' for uploading property images; generates presigned URLs enabling image uploads to R2 storage

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

presign_image_batch Rate-limited

presign_image_batch 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": {
    "presign_image_batch": {
      "limits": [
        {
          "counter": "presign_image_batch_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 Rentalot MCP Server, so you can run agents against it safely.

FAQ

Questions about presign_image_batch

What does the presign_image_batch tool do? +

Use to get presigned URLs for uploading up to 20 property images at once. Returns an upload URL and R2 key for each image. Write operation — requires Pro tier or higher. It is categorised as a Write tool in the Rentalot MCP 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 presign_image_batch? +

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

What risk level is presign_image_batch? +

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

Can I rate-limit presign_image_batch? +

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

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

presign_image_batch is provided by the Rentalot MCP Server MCP server (rentalot-ai/rentalot-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.