vast_update_companion · AdButler MCP: Risk & Policy

WHAT IT DOES

What vast_update_companion does on AdButler

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

PARAMETERS

Parameter	Type	Required	Description
`id`	number	Yes	VAST companion ID
`name`	string	—	Companion name
`width`	number	—	Companion width in pixels
`height`	number	—	Companion height in pixels

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why vast_update_companion needs a policy

This tool modifies existing VAST companion configurations reversibly. VAST (Video Ad Serving Template) companions are advertising assets, and updating them changes ad campaign data. This is a Write operation because it modifies data without permanently deleting it.

From the tool's definition Tool name includes 'update' and description states 'Update an existing VAST companion', indicating modification of existing data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vast_update_companion Rate-limited

vast_update_companion 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": {
    "vast_update_companion": {
      "limits": [
        {
          "counter": "vast_update_companion_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 AdButler, so you can run agents against it safely.

FAQ

Questions about vast_update_companion

What does the vast_update_companion tool do? +

Update an existing VAST companion. It is categorised as a Write tool in the AdButler MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does vast_update_companion accept? +

vast_update_companion accepts 4 parameters: id, name, width, height. Required: id. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on vast_update_companion? +

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

What risk level is vast_update_companion? +

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

Can I rate-limit vast_update_companion? +

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

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

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