roll_custom · Dice Roller MCP Server MCP: Risk & Policy

WHAT IT DOES

What roll_custom does on Dice Roller MCP Server

AI agents invoke roll_custom to trigger actions in Dice Roller MCP Server. 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 roll_custom needs a policy

This tool executes a randomized computation (dice rolling) with arbitrary inputs. It has no persistent side effects, no data modification, and no financial implications. Severity is low because misuse is essentially harmless — the worst outcome is an unintended random number result.

From the tool's definition 'Roll any number of any-sided dice with a modifier and optional label' — executes a dice-rolling operation with configurable parameters

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

roll_custom Rate-limited

roll_custom 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": {
    "roll_custom": {
      "limits": [
        {
          "counter": "roll_custom_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 Dice Roller MCP Server, so you can run agents against it safely.

FAQ

Questions about roll_custom

What does the roll_custom tool do? +

Roll any number of any-sided dice with a modifier and optional label. It is categorised as a Execute tool in the Dice Roller MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on roll_custom? +

Register the Dice Roller MCP Server MCP server in PolicyLayer and add a rule for roll_custom: 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 Dice Roller MCP Server. Nothing to install.

What risk level is roll_custom? +

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

Can I rate-limit roll_custom? +

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

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

roll_custom is provided by the Dice Roller MCP Server MCP server (swayam-mishra/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.