guide_add · Open Brush MCP Server MCP: Risk & Policy

WHAT IT DOES

What guide_add does on Open Brush MCP Server

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

WHY IT NEEDS A POLICY

Why guide_add needs a policy

Adding a guide is a creative operation that modifies the scene state by introducing a new, non-destructive element. It falls under Write category as it creates/adds data reversibly. Severity is low because guides are drawing aids with no impact on the final artwork, financial systems, or external operations. The blast radius of misuse is minimal—unwanted guides can be easily removed.

From the tool's definition Tool name 'guide_add' and description 'Adds a guide to the scene' indicate creation of a new scene element. This is a reversible write operation that creates data (a guide) without executing external code or deleting existing content.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

guide_add Rate-limited

guide_add 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": {
    "guide_add": {
      "limits": [
        {
          "counter": "guide_add_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 Open Brush MCP Server, so you can run agents against it safely.

FAQ

Questions about guide_add

What does the guide_add tool do? +

Adds a guide to the scene. It is categorised as a Write tool in the Open Brush 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 guide_add? +

Register the Open Brush MCP Server MCP server in PolicyLayer and add a rule for guide_add: 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 Open Brush MCP Server. Nothing to install.

What risk level is guide_add? +

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

Can I rate-limit guide_add? +

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

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

guide_add is provided by the Open Brush MCP Server MCP server (moz411/openbrush-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.