add_account_document · FixPayment MCP: Risk & Policy

WHAT IT DOES

What add_account_document does on FixPayment

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

WHY IT NEEDS A POLICY

Why add_account_document needs a policy

This tool modifies account state by adding a document attachment, making it a Write operation (creates/modifies data reversibly). Severity is medium because while document attachment is reversible and doesn't involve financial transactions directly, it operates on creditor account records in a financial context (FixPayment is a payment/creditor management system), and improper document attachment could affect…

From the tool's definition Tool description states 'Attach a single document' to an existing account, which is a modification operation that creates/adds data to an account record.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_account_document Rate-limited

add_account_document 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": {
    "add_account_document": {
      "limits": [
        {
          "counter": "add_account_document_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 FixPayment, so you can run agents against it safely.

FAQ

Questions about add_account_document

What does the add_account_document tool do? +

Attach a single document (PDF/image/Word) to an existing account. It is categorised as a Write tool in the FixPayment MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_account_document? +

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

What risk level is add_account_document? +

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

Can I rate-limit add_account_document? +

Yes. Add a rate_limit block to the add_account_document 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_account_document completely? +

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

add_account_document is provided by the FixPayment MCP server (prmail/fixpayment_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.