generate_pin · TinyFn MCP: Risk & Policy

WHAT IT DOES

What generate_pin does on TinyFn

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

PARAMETERS

Parameter	Type	Required	Description
`length`	integer	—	PIN length

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why generate_pin needs a policy

An AI agent can call generate_pin faster than any human can review — one bad instruction and it creates or modifies resources in TinyFn by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

generate_pin Rate-limited

generate_pin 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": {
    "generate_pin": {
      "limits": [
        {
          "counter": "generate_pin_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 TinyFn, so you can run agents against it safely.

FAQ

Questions about generate_pin

What does the generate_pin tool do? +

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

What parameters does generate_pin accept? +

generate_pin accepts 1 parameter: length. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on generate_pin? +

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

What risk level is generate_pin? +

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

Can I rate-limit generate_pin? +

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

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

generate_pin is provided by the TinyFn MCP server (https://api.tinyfn.io/mcp/all/). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

generate_pin is one line of TinyFn's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

Teams ship this data inside their own products. See what a licence covers →