spreader_run · Cartridge MCP: Risk & Policy

WHAT IT DOES

What spreader_run does on Cartridge

AI agents invoke spreader_run to trigger actions in Cartridge. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why spreader_run needs a policy

The tool performs an execution action ('Execute one modify-spread-tool iteration') on a target entity. While the description lacks specifics about what 'modify-spread-tool' does, the use of 'run' combined with 'execute' and action on a 'target' indicates this triggers external operations whose effects depend on runtime arguments.

From the tool's definition Tool name contains 'run' and description states 'Execute one modify-spread-tool iteration on a target', indicating execution of operations with external effects.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

spreader_run Rate-limited

spreader_run stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "spreader_run": {
      "limits": [
        {
          "counter": "spreader_run_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Cartridge, so you can run agents against it safely.

FAQ

Questions about spreader_run

What does the spreader_run tool do? +

Execute one modify-spread-tool iteration on a target. It is categorised as a Execute tool in the Cartridge MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on spreader_run? +

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

What risk level is spreader_run? +

spreader_run is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit spreader_run? +

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

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

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