subtract · Study MCP: Risk & Policy

WHAT IT DOES

What subtract does on Study

AI agents invoke subtract to trigger actions in Study. 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 subtract needs a policy

The tool executes a mathematical operation (subtraction) on two numbers. While it has no side effects and is essentially a read/compute operation, it does perform computation rather than simply retrieving stored data. Given the server context (math tools: add, subtract, multiply, divide), this is a pure arithmetic tool with minimal risk. Severity is low as misuse has essentially no blast radius.

From the tool's definition 'Subtract two numbers' — performs a arithmetic computation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

subtract Rate-limited

subtract 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": {
    "subtract": {
      "limits": [
        {
          "counter": "subtract_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 Study, so you can run agents against it safely.

FAQ

Questions about subtract

What does the subtract tool do? +

Subtract two numbers. It is categorised as a Execute tool in the Study MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on subtract? +

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

What risk level is subtract? +

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

Can I rate-limit subtract? +

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

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

subtract is provided by the Study MCP server (lucs1590/study-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.