batch_render · RendrKit MCP: Risk & Policy

WHAT IT DOES

What batch_render does on RendrKit

AI agents invoke batch_render to trigger actions in RendrKit. 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 batch_render needs a policy

This tool executes an external API operation (bulk image rendering) that produces real-world side effects (consuming API credits, generating up to 20 images per call). It is not a simple write of user-supplied data but an execution of a compute-intensive external service. Misuse by an AI agent could rapidly exhaust API quotas or generate large volumes of unintended content, warranting high severity.

From the tool's definition 'Generate multiple images from the same template with different data' and 'Up to 20 items per batch' — triggers external AI image generation operations at scale

Risk signalsBulk/mass operation — affects multiple targets

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

batch_render Rate-limited

batch_render 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": {
    "batch_render": {
      "limits": [
        {
          "counter": "batch_render_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 RendrKit, so you can run agents against it safely.

FAQ

Questions about batch_render

What does the batch_render tool do? +

Generate multiple images from the same template with different data. Perfect for e-commerce catalogs, certificates, social media series. Up to 20 items per batch. It is categorised as a Execute tool in the RendrKit MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on batch_render? +

Register the RendrKit MCP server in PolicyLayer and add a rule for batch_render: 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 RendrKit. Nothing to install.

What risk level is batch_render? +

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

Can I rate-limit batch_render? +

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

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

batch_render is provided by the RendrKit MCP server (vbiff/rendrkit-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.