use_spell_slot · DM20 Protocol MCP: Risk & Policy

WHAT IT DOES

What use_spell_slot does on DM20 Protocol

AI agents use use_spell_slot to create or update resources in DM20 Protocol — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your DM20 Protocol environment.

WHY IT NEEDS A POLICY

Why use_spell_slot needs a policy

Based on the tool name alone, 'use_spell_slot' most likely modifies a character's spell slot state (marking a slot as used/expended) within the D&D campaign management system. This is a reversible state change (slots restore on rest), placing it in the Write category. Confidence is low due to the empty description.

From the tool's definition Tool name: 'use_spell_slot' — description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

use_spell_slot Rate-limited

use_spell_slot 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": {
    "use_spell_slot": {
      "limits": [
        {
          "counter": "use_spell_slot_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches DM20 Protocol, so you can run agents against it safely.

FAQ

Questions about use_spell_slot

What does the use_spell_slot tool do? +

use_spell_slot. It is categorised as a Write tool in the DM20 Protocol MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on use_spell_slot? +

Register the DM20 Protocol MCP server in PolicyLayer and add a rule for use_spell_slot: 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 DM20 Protocol. Nothing to install.

What risk level is use_spell_slot? +

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

Can I rate-limit use_spell_slot? +

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

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

use_spell_slot is provided by the DM20 Protocol MCP server (polloinfilzato/dm20-protocol). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.