combine_images · Nano Banana MCP Server MCP: Risk & Policy

WHAT IT DOES

What combine_images does on Nano Banana MCP Server

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

WHY IT NEEDS A POLICY

Why combine_images needs a policy

This tool creates new image outputs by combining existing images, which is a Write operation (creates/modifies data reversibly). It does not execute arbitrary code, delete data, move funds, or trigger external operations with unpredictable side effects.

From the tool's definition Tool description explicitly states 'Stitch multiple images together' and 'creating panoramas, sprite sheets, or image collages' — these are reversible creation/modification operations that combine existing images into new outputs without destroying originals.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

combine_images Rate-limited

combine_images 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": {
    "combine_images": {
      "limits": [
        {
          "counter": "combine_images_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 Nano Banana MCP Server, so you can run agents against it safely.

FAQ

Questions about combine_images

What does the combine_images tool do? +

Stitch multiple images together horizontally, vertically, or in a grid layout. Perfect for creating panoramas, sprite sheets, or image collages. It is categorised as a Write tool in the Nano Banana 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 combine_images? +

Register the Nano Banana MCP Server MCP server in PolicyLayer and add a rule for combine_images: 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 Nano Banana MCP Server. Nothing to install.

What risk level is combine_images? +

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

Can I rate-limit combine_images? +

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

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

combine_images is provided by the Nano Banana MCP Server MCP server (lyalindotcom/nano-banana-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.