list_contacts

THE RISK

Low Risk

Why list_contacts needs a policy

This tool only retrieves contact information without side effects. It matches the Read category definition: retrieves or queries data with no side effects. The severity is low because exposing a list of contacts, while potentially sensitive, does not enable financial harm, data destruction, or system-level damage without additional tools.

From the tool's definition Tool name 'list_contacts' and description 'Retrieves all contacts in a Xero organisation' clearly indicate a query/retrieval operation with no modification or deletion of data.

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

POLICY

How to control list_contacts

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

policy.json

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

list_contacts 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 Xero 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 Xero MCP Server tools

Write create_bank_transactions Creates one or more spent or received money transaction. Only use this tool when user has Write create_contacts Creates one or multiple contacts in a Xero organisation. Only use this tool when user has Write update_bank_transaction Updates an existing spent or received money transaction by its Xero bank transaction ID Write update_invoice Updates an existing sales invoice or purchase bill (typically a draft) to change fields li Other authenticate Authenticate with Xero using OAuth2 Read get_balance_sheet Returns a balance sheet for the end of the month of the specified date. It also returns th Read get_bank_transaction Retrieves a single spent or received money transaction by its Xero bank transaction ID Read get_invoice Retrieves a single sales invoice or purchase bill by its Xero invoice ID

All 15 Xero 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_contacts

What does the list_contacts tool do? +

Retrieves all contacts in a Xero organisation. It is categorised as a Read tool in the Xero MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_contacts? +

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

What risk level is list_contacts? +

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

Can I rate-limit list_contacts? +

Yes. Add a rate_limit block to the list_contacts 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_contacts completely? +

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

list_contacts is provided by the Xero MCP Server MCP server (john-zhang-dev/xero-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Xero MCP Server tool call.

Start from Xero 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 →