This record as markdown: /tools/io-tinyfn-tinyfn/is-zero.md
What is_zero does on TinyFn
AI agents call is_zero to retrieve information from TinyFn without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
number | number | Yes | The number to check |
Parameters from the server's own tool schema.
Why is_zero is rated Low
This is a deterministic validation/check function that reads input and returns a boolean result. It performs no writes, deletions, code execution, or financial operations. The low severity reflects that misuse cannot cause harm—it merely returns information about a number's value.
From the tool's definition Tool name 'is_zero' and description 'Check if a number is zero' indicate a pure query operation that retrieves or evaluates a numeric property with no side effects, no data modification, and no external operations.
Attacks that exploit this kind of access
The rule that runs is_zero safely
PolicyLayer is an MCP gateway: it sits between your AI agents and TinyFn, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For is_zero, this is the rule to start with:
is_zero is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect TinyFn, apply this rule, and every is_zero call is checked against it from then on.
Questions about is_zero
Check if a number is zero. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
is_zero accepts 1 parameter: number. Required: number. The full parameter table on this page comes from the server's own tool schema.
Register the TinyFn MCP server in PolicyLayer and add a rule for is_zero: 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.
is_zero is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the is_zero 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 is_zero. 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.
is_zero 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.
More on TinyFn, and thousands of servers like it.
This server
Across the catalogue