enhanced_capture · MCP ScreenCatch MCP: Risk & Policy

WHAT IT DOES

What enhanced_capture does on MCP ScreenCatch

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

WHY IT NEEDS A POLICY

Why enhanced_capture needs a policy

This tool captures screenshots and saves them to disk. Saving files is a Write operation — it creates new image files on the filesystem. The tool does not delete or overwrite existing data, execute arbitrary code, or move money.

From the tool's definition 'Complete capture workflow', 'Auto-merge multiple captures', 'automatically saving timestamped images to a configurable directory'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

enhanced_capture Rate-limited

enhanced_capture 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": {
    "enhanced_capture": {
      "limits": [
        {
          "counter": "enhanced_capture_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 MCP ScreenCatch, so you can run agents against it safely.

FAQ

Questions about enhanced_capture

What does the enhanced_capture tool do? +

RECOMMENDED: Complete capture workflow with (1) Description input, (2) Multi-region capture in one session (Enter=continue, Shift+Enter=finish), (3) Auto-merge multiple captures. Use this for all screenshot requests unless user specifically asks for basic single capture. It is categorised as a Write tool in the MCP ScreenCatch MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on enhanced_capture? +

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

What risk level is enhanced_capture? +

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

Can I rate-limit enhanced_capture? +

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

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

enhanced_capture is provided by the MCP ScreenCatch MCP server (johnelamont/mcp-screencatch). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.