vast42_update_media_file · AdButler MCP: Risk & Policy

WHAT IT DOES

What vast42_update_media_file does on AdButler

AI agents use vast42_update_media_file 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 4.2 media file ID
`name`	string	—	Media file name
`width`	number	—	Width in pixels
`height`	number	—	Height in pixels
`bitrate`	number	—	Bitrate in kbps
`mime_type`	string	—	MIME type

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why vast42_update_media_file needs a policy

This tool modifies advertising media files (VAST 4.2 format), which are reversible changes to ad campaign assets. It does not delete data (would be Destructive), execute arbitrary code (would be Execute), or involve financial transactions (would be Financial).

From the tool's definition Tool name contains 'update' and description states 'Update a VAST 4.2 media file', indicating modification of existing advertising content.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vast42_update_media_file Rate-limited

vast42_update_media_file 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": {
    "vast42_update_media_file": {
      "limits": [
        {
          "counter": "vast42_update_media_file_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 vast42_update_media_file

What does the vast42_update_media_file tool do? +

Update a VAST 4.2 media file. 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 vast42_update_media_file accept? +

vast42_update_media_file accepts 6 parameters: id, name, width, height, bitrate, mime_type. Required: id. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on vast42_update_media_file? +

Register the AdButler MCP server in PolicyLayer and add a rule for vast42_update_media_file: 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 vast42_update_media_file? +

vast42_update_media_file is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit vast42_update_media_file? +

Yes. Add a rate_limit block to the vast42_update_media_file 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 vast42_update_media_file completely? +

Set action: deny in the PolicyLayer policy for vast42_update_media_file. 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 vast42_update_media_file? +

vast42_update_media_file 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.