update_variant

THE RISK

Medium Risk

Why update_variant needs a policy

This tool modifies product variant information reversibly (variant details can be changed again or reverted). The blast radius is medium because incorrect variant updates could affect product listings, pricing, or availability, but the operation is not destructive, does not move money, and is reversible.

From the tool's definition Tool name 'update_variant' and description 'Update an existing product variant' indicate modification of existing data structure without deletion or destruction.

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

POLICY

How to control update_variant

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_variant": {
      "limits": [
        {
          "counter": "update_variant_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

update_variant 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.

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

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Mcp Afip tools

Financial authorize_transaction Authorize a transaction (reserve funds without capturing) via Braintree GraphQL authorizeP Financial cancel_collection Cancel a scheduled collection request Financial cancel_credit Cancel an authorized-but-uncaptured credit payment. Financial cancel_payment Attempt to cancel a payment that has not yet settled. Iniciador endpoint: POST /payments/{ Financial cancel_payment_intent Cancel a payment intent that has not yet been captured. Fails on already-captured intents; Financial cancel_recurrence Cancel an active recurrence. Future charges will stop; already-charged cycles are untouche Financial cancel_subscription Cancel a subscription by ID Financial revoke_token Revoke an issued access_token or refresh_token at POST /v1/token/revoke. Use to terminate

All 1300 Mcp Afip tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about update_variant

What does the update_variant tool do? +

Update an existing product variant. It is categorised as a Write tool in the Mcp Afip 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_variant? +

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

What risk level is update_variant? +

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

Can I rate-limit update_variant? +

Yes. Add a rate_limit block to the update_variant 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_variant completely? +

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

update_variant is provided by the Mcp Afip MCP server (codespar/mcp-dev-latam). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mcp Afip tool call.

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

CHECK YOUR STACK →