set_start · vidMagik- MCP: Risk & Policy

WHAT IT DOES

What set_start does on vidMagik-mcp

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

WHY IT NEEDS A POLICY

Why set_start needs a policy

This tool modifies clip metadata (start time) rather than destructively removing content or executing arbitrary operations. It can be undone by setting a different start time. However, it affects video composition and rendering output, which justifies medium severity—an agent could misuse it to distort video sequences or corrupt intended timing.

From the tool's definition Tool named 'set_start' with description 'Set clip start time.' modifies a property of a video clip object, which is a reversible data modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_start Rate-limited

set_start 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": {
    "set_start": {
      "limits": [
        {
          "counter": "set_start_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 vidMagik-mcp, so you can run agents against it safely.

FAQ

Questions about set_start

What does the set_start tool do? +

Set clip start time. It is categorised as a Write tool in the vidMagik-mcp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_start? +

Register the vidMagik- MCP server in PolicyLayer and add a rule for set_start: 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 vidMagik-mcp. Nothing to install.

What risk level is set_start? +

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

Can I rate-limit set_start? +

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

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

set_start is provided by the vidMagik- MCP server (vizionik25/vidmagik-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.