create_budget · Finance App MCP: Risk & Policy

WHAT IT DOES

What create_budget does on Finance App

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

WHY IT NEEDS A POLICY

Why create_budget needs a policy

The tool creates a new budget record, which is a reversible write operation—budgets can be modified or deleted later (as evidenced by the delete_budget sibling tool). This is not Destructive (not irreversible), not Financial (does not move money or create obligations, only creates a budget plan), and not Execute (does not run arbitrary code or trigger external side effects).

From the tool's definition Tool name 'create_budget' indicates creation of a new budget object. The server context is a double-entry accounting service managing financial data via PostgreSQL.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_budget Rate-limited

create_budget 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": {
    "create_budget": {
      "limits": [
        {
          "counter": "create_budget_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

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

FAQ

Questions about create_budget

What does the create_budget tool do? +

create_budget. It is categorised as a Write tool in the Finance App MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_budget? +

Register the Finance App MCP server in PolicyLayer and add a rule for create_budget: 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 Finance App. Nothing to install.

What risk level is create_budget? +

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

Can I rate-limit create_budget? +

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

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

create_budget is provided by the Finance App MCP server (youssefaltai/finance-app). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.