update_image · BookStack MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_image does on BookStack MCP Server

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

WHY IT NEEDS A POLICY

Why update_image needs a policy

update_image modifies image metadata/details rather than creating or deleting. This is a Write operation because it changes existing data in a reversible manner. Severity is medium rather than low because images in a wiki context could be associated with sensitive content or important documentation, and unauthorized updates could deface or corrupt documentation.

From the tool's definition Tool name is 'update_image' and description states 'Update image details', indicating modification of existing image metadata or properties.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_image Rate-limited

update_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": {
    "update_image": {
      "limits": [
        {
          "counter": "update_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 BookStack MCP Server, so you can run agents against it safely.

FAQ

Questions about update_image

What does the update_image tool do? +

Update image details. It is categorised as a Write tool in the BookStack 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 update_image? +

Register the BookStack MCP Server MCP server in PolicyLayer and add a rule for update_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 BookStack MCP Server. Nothing to install.

What risk level is update_image? +

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

Can I rate-limit update_image? +

Yes. Add a rate_limit block to the update_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 update_image completely? +

Set action: deny in the PolicyLayer policy for update_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 update_image? +

update_image is provided by the BookStack MCP Server MCP server (lautarobarba/bookstack_mcp_server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.