send_video · Viber MCP: Risk & Policy

WHAT IT DOES

What send_video does on Viber

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

WHY IT NEEDS A POLICY

Why send_video needs a policy

This tool creates and transmits new data (a video message) to a Viber user. The action is reversible in principle (messages can be deleted on most platforms) and has no destructive, financial, or code-execution components. It falls under Write rather than Read because it actively creates/transmits data rather than retrieving it.

From the tool's definition Tool sends video content to Viber users ('Send an MP4 video...to a Viber user'). This creates a new message/modifies user's message history reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_video Rate-limited

send_video 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": {
    "send_video": {
      "limits": [
        {
          "counter": "send_video_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 Viber, so you can run agents against it safely.

FAQ

Questions about send_video

What does the send_video tool do? +

Send an MP4 video (≤26MB, ≤180s) to a Viber user via public URL. Use when sharing short video clips. Do not use for audio-only files — use send_file instead. Requires file size in bytes; ask the user if unknown. Returns message_token for delivery tracking. It is categorised as a Write tool in the Viber MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on send_video? +

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

What risk level is send_video? +

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

Can I rate-limit send_video? +

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

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

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