array_union

Get union of two arrays.

SERVERTinyFn SOURCEhttps://api.tinyfn.io/mcp/all/

Low RISK CLASS

Category Read

Parameters 22 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-tinyfn-tinyfn/array-union.md

WHAT IT DOES

What array_union does on TinyFn

AI agents call array_union 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
`array1`	string	Yes	First comma-separated array
`array2`	string	Yes	Second comma-separated array

Parameters from the server's own tool schema.

RISK

Why array_union is rated Low

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

RECOMMENDED RULE

The rule that runs array_union 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 array_union, this is the rule to start with:

array_union Allowed

array_union is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "array_union": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect TinyFn, apply this rule, and every array_union call is checked against it from then on.

FAQ

Questions about array_union

What does the array_union tool do? +

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.

What parameters does array_union accept? +

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.

How do I enforce a policy on array_union? +

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.

What risk level is array_union? +

array_union is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit array_union? +

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.

How do I block array_union completely? +

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.

What MCP server provides array_union? +

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.

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