Update fields on an existing applicant. Send only the fields you want to change.
AI agents use update_applicant to create or update resources in Mcp Afip — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mcp Afip environment.
The tool modifies existing applicant records, which is reversible (fields can be changed again or reverted). In the context of an Argentine tax authority system, applicant data likely includes business or taxpayer information. This is a Write operation as it creates or modifies data reversibly without irreversible deletion or financial transaction processing.
From the tool's definition Tool name is 'update_applicant' and description states 'Update fields on an existing applicant. Send only the fields you want to change.' This is a modification operation on applicant data.
Documented attack patterns abuse exactly the kind of access update_applicant gives an agent:
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_applicant:
{
"version": "1",
"default": "deny",
"tools": {
"update_applicant": {
"limits": [
{
"counter": "update_applicant_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_applicant 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.
Free to start. No card required.
Update fields on an existing applicant. Send only the fields you want to change. 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.
Register the Mcp Afip MCP server in PolicyLayer and add a rule for update_applicant: 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.
update_applicant is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the update_applicant 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.
Set action: deny in the PolicyLayer policy for update_applicant. 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.
update_applicant 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.
Start from Mcp Afip, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
1300 Mcp Afip tools catalogued and risk-classified — across an index of 43,000+ MCP servers.