capture_image · mcpXL30 MCP: Risk & Policy

WHAT IT DOES

What capture_image does on mcpXL30

AI agents use capture_image to create or update resources in mcpXL30 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your mcpXL30 environment.

WHY IT NEEDS A POLICY

Why capture_image needs a policy

This tool creates and persists new image files on the microscope console host's filesystem. While this is reversible (files can be deleted), it modifies the state of the system by adding new data. It does not execute arbitrary commands, destroy existing data, or involve financial transactions.

From the tool's definition The tool description explicitly states it will 'Write a TIFF image to a path visible to the XL30 console host.' This is a create/write operation that produces new data artifacts on the microscope's host system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

capture_image Rate-limited

capture_image 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": {
    "capture_image": {
      "limits": [
        {
          "counter": "capture_image_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 mcpXL30, so you can run agents against it safely.

FAQ

Questions about capture_image

What does the capture_image tool do? +

Write a TIFF image to a path visible to the XL30 console host. It is categorised as a Write tool in the mcpXL30 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on capture_image? +

Register the mcpXL30 MCP server in PolicyLayer and add a rule for capture_image: 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 mcpXL30. Nothing to install.

What risk level is capture_image? +

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

Can I rate-limit capture_image? +

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

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

capture_image is provided by the mcpXL30 MCP server (tspspi/mcpxl30). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.