list_businesses

THE RISK

Low Risk

Why list_businesses needs a policy

This tool retrieves and enumerates existing business entities from the Wave Accounting system. It performs a read-only query with pagination support. There are no modifications, deletions, or financial transactions involved. The low severity reflects minimal blast radius; even if misused by an agent, listing businesses reveals no sensitive financial data beyond entity names and IDs, and causes no harm.

From the tool's definition Tool name is 'list_businesses' and description states 'List all available Wave businesses with pagination' — both indicate a retrieval/query operation with no side effects.

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

POLICY

How to control list_businesses

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_businesses": {}
  }
}

list_businesses is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

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

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Wave Accounting MCP Server tools

Write create_expense_from_receipt Create an expense in Wave from receipt data. Vendor is optional - expenses can be created Write create_income_from_payment Create an income transaction in Wave from payment/receipt data. Customer is optional - inc Write set_business Set the active business for operations Read debug_accounts Debug tool: List ALL accounts with their types and subtypes to help diagnose account detec Read get_expense_accounts Get a list of expense accounts to help categorize receipts Read get_income_accounts Get a list of income accounts to help categorize income transactions Read search_customer Search for an existing customer in Wave Read search_vendor Search for an existing vendor in Wave (vendors must be created manually in Wave

All 9 Wave Accounting MCP Server tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about list_businesses

What does the list_businesses tool do? +

List all available Wave businesses with pagination. It is categorised as a Read tool in the Wave Accounting MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_businesses? +

Register the Wave Accounting MCP Server MCP server in PolicyLayer and add a rule for list_businesses: 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 Wave Accounting MCP Server. Nothing to install.

What risk level is list_businesses? +

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

Can I rate-limit list_businesses? +

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

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

list_businesses is provided by the Wave Accounting MCP Server MCP server (vinnividivicci/wave_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Wave Accounting MCP Server tool call.

Start from Wave Accounting MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →