update_invoice · FacturaHub MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_invoice does on FacturaHub MCP Server

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

WHY IT NEEDS A POLICY

Why update_invoice needs a policy

The tool modifies invoice data (items, notes, tax rate, currency, dates) but operates only on draft invoices, which are reversible states. This is clearly a Write operation—it creates or modifies data without permanent destruction. While invoicing is financial in nature, the action itself is modification of a document rather than actual money movement or financial commitment (those would be Financial category).

From the tool's definition Tool description: 'Update a draft invoice — change items, notes, tax rate, currency, or dates.' This modifies financial documents (invoices) by updating their content reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_invoice Rate-limited

update_invoice 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": {
    "update_invoice": {
      "limits": [
        {
          "counter": "update_invoice_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 FacturaHub MCP Server, so you can run agents against it safely.

FAQ

Questions about update_invoice

What does the update_invoice tool do? +

[FacturaHub] Update a draft invoice — change items, notes, tax rate, currency, or dates. It is categorised as a Write tool in the FacturaHub 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 update_invoice? +

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

What risk level is update_invoice? +

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

Can I rate-limit update_invoice? +

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

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

update_invoice is provided by the FacturaHub MCP Server MCP server (santy1422/facturahub-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.