AI agents call array_union to retrieve information from TinyFn without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
array1 | string | Yes | First comma-separated array |
array2 | string | Yes | Second comma-separated array |
Parameters from the server's own tool schema.
This is a deterministic utility function that performs a read-only computation on array inputs. It combines two arrays into a single array containing unique elements, returning a result without modifying inputs or creating side effects. This aligns with the Read category for tools that retrieve or compute data with no mutations or external effects.
From the tool's definition Tool name 'array_union' and description 'Get union of two arrays' indicate a pure mathematical/set operation that retrieves a computed result without side effects.
Attacks that exploit this kind of access
Get union of two arrays. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
array_union accepts 2 parameters: array1, array2. Required: array1, array2. 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 array_union: 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.
array_union 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 array_union 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 array_union. 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.
array_union 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.
array_union 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.
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