create_receipt · ProofSlip MCP: Risk & Policy

WHAT IT DOES

What create_receipt does on ProofSlip

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

WHY IT NEEDS A POLICY

Why create_receipt needs a policy

The tool creates a new receipt object to record an event within a verification system. This is a Write action (creates data) rather than Read (no retrieval), Destructive (data is not deleted), Execute (no external commands/code), Financial (no money movement), or Other.

From the tool's definition Tool name 'create_receipt' and description 'Create a ProofSlip receipt to record that something happened' indicate creation of a new object, which is a reversible Write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_receipt Rate-limited

create_receipt 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_receipt": {
      "limits": [
        {
          "counter": "create_receipt_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 ProofSlip, so you can run agents against it safely.

FAQ

Questions about create_receipt

What does the create_receipt tool do? +

Create a ProofSlip receipt to record that something happened. It is categorised as a Write tool in the ProofSlip 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_receipt? +

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

What risk level is create_receipt? +

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

Can I rate-limit create_receipt? +

Yes. Add a rate_limit block to the create_receipt 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_receipt completely? +

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

create_receipt is provided by the ProofSlip MCP server (@proofslip/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.