annotate_last_image · Visual Annotation MCP: Risk & Policy

WHAT IT DOES

What annotate_last_image does on Visual Annotation MCP

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

WHY IT NEEDS A POLICY

Why annotate_last_image needs a policy

The tool likely draws/writes annotations on the last captured screenshot image. This is a Write operation as it modifies or overlays data on an existing image. Confidence is low because the description is empty, so we rely on the tool name and server context. Annotations are typically reversible (you can take a new screenshot), so Destructive is unlikely.

From the tool's definition Tool name 'annotate_last_image' and server description mentions 'draw annotations with color contrast selection' on screenshots

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

annotate_last_image Rate-limited

annotate_last_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": {
    "annotate_last_image": {
      "limits": [
        {
          "counter": "annotate_last_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 Visual Annotation MCP, so you can run agents against it safely.

FAQ

Questions about annotate_last_image

What does the annotate_last_image tool do? +

annotate_last_image. It is categorised as a Write tool in the Visual Annotation MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on annotate_last_image? +

Register the Visual Annotation MCP server in PolicyLayer and add a rule for annotate_last_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 Visual Annotation MCP. Nothing to install.

What risk level is annotate_last_image? +

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

Can I rate-limit annotate_last_image? +

Yes. Add a rate_limit block to the annotate_last_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 annotate_last_image completely? +

Set action: deny in the PolicyLayer policy for annotate_last_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 annotate_last_image? +

annotate_last_image is provided by the Visual Annotation MCP server (mstocker1/visual_annotation_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.