create_estimate

THE RISK

Critical Risk

Why create_estimate needs a policy

Creating a financial estimate/quote commits to pricing terms and can be converted to invoices, which directly initiates financial obligations. In the context of AP2 (Agent-to-Agent Payment Protocol), this is a precursor to financial transactions.

From the tool's definition Create an estimate (quote). CustomerRef and Line items required. Estimates can later be converted to invoices.

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

POLICY

How to control create_estimate

PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Ap2, and nothing reaches the server without passing your rules. This is the rule we recommend for create_estimate:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_estimate": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

Any call to create_estimate is blocked until a human approves it. The rest of the server keeps working.

Create a free account and register Mcp Ap2 — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

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Free to start. No card required.

EXPLORE

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Go deeper

Critical-risk tools in Mcp Ap2 → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Human-in-the-loop → When a tool call should wait for a person — and when policy can decide alone.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
How to Add Spending Controls to Any MCP Agent →
Rate Limiting MCP Tool Calls: A Practical Guide →

FAQ

Questions about create_estimate

What does the create_estimate tool do? +

Create an estimate (quote). CustomerRef and Line items required. Estimates can later be converted to invoices. It is categorised as a Financial tool in the Mcp Ap2 MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on create_estimate? +

Register the Mcp Ap2 MCP server in PolicyLayer and add a rule for create_estimate: 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 Mcp Ap2. Nothing to install.

What risk level is create_estimate? +

create_estimate is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit create_estimate? +

Yes. Add a rate_limit block to the create_estimate 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_estimate completely? +

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

create_estimate is provided by the Mcp Ap2 MCP server (@codespar/mcp-ap2). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mcp Ap2 tool call.

Start from Mcp Ap2, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →