splitwise_add_friend · Splitwise MCP Server MCP

WHAT IT DOES

What splitwise_add_friend does on Splitwise MCP Server

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

WHY IT NEEDS A POLICY

Why splitwise_add_friend needs a policy

This tool creates or modifies the user's social graph by adding friends, which is a reversible Write operation. While not destructive, it modifies application state and can affect expense-sharing permissions and financial workflows.

From the tool's definition Tool creates a new friend relationship or adds an existing user to a friend list. The description states 'Add a new friend' and 'If creating a new user', indicating data creation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

splitwise_add_friend Rate-limited

splitwise_add_friend 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": {
    "splitwise_add_friend": {
      "limits": [
        {
          "counter": "splitwise_add_friend_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about splitwise_add_friend

What does the splitwise_add_friend tool do? +

Add a new friend. If the user exists, first_name and last_name are ignored. If creating a new user, first_name is required. It is categorised as a Write tool in the Splitwise MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on splitwise_add_friend? +

Register the Splitwise MCP Server MCP server in PolicyLayer and add a rule for splitwise_add_friend: 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 Splitwise MCP Server. Nothing to install.

What risk level is splitwise_add_friend? +

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

Can I rate-limit splitwise_add_friend? +

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

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

splitwise_add_friend is provided by the Splitwise MCP Server MCP server (svarun115/splitwise-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.