add

THE RISK

Low Risk

Why add needs a policy

This tool performs a simple mathematical addition of two numbers. It has no side effects, does not read from or write to any data store, does not execute code or commands, and involves no financial transactions. It is a stateless computation utility, placing it firmly in the 'Other' category.

From the tool's definition Tool name 'add' and description 'Add two numbers.' indicate a pure arithmetic operation with no data retrieval, storage, execution, or financial effects.

Documented attack patterns abuse exactly the kind of access add gives an agent:

POLICY

How to control add

PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Arena, and nothing reaches the server without passing your rules. This is the rule we recommend for add:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add": {
      "limits": [
        {
          "counter": "add_rate",
          "window": "minute",
          "max": 60,
          "scope": "grant"
        }
      ]
    }
  }
}

add gets a rate cap, and everything else on the server is denied unless you say otherwise.

Create a free account and register Mcp Arena — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

SET A RULE FOR THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Mcp Arena tools

Execute multiply Multiply two numbers. Read echo Echo back the input text. Other greet Greet someone by name.

All 4 Mcp Arena tools →

Other tools on other servers

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Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Tool risk categories → How PolicyLayer classifies MCP tools by what they can do.
MCP tool → What an MCP tool is and how clients discover and call it.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about add

What does the add tool do? +

Add two numbers. It is categorised as a Other tool in the Mcp Arena MCP Server, which means it performs auxiliary operations.

How do I enforce a policy on add? +

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

What risk level is add? +

add is a Other tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit add? +

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

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

add is provided by the Mcp Arena MCP server (satyamsingh8306/mcp_arena). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mcp Arena tool call.

Start from Mcp Arena, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →