group_by_length
Group items by their string length.
This record as markdown: /tools/io-tinyfn-tinyfn/group-by-length.md
What group_by_length does on TinyFn
AI agents call group_by_length 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 |
|---|---|---|---|
items | string | Yes | Comma-separated items |
Parameters from the server's own tool schema.
Why group_by_length is rated Low
This is a pure data transformation utility that analyzes and categorizes input based on string length. It does not modify data, delete data, execute code, commit financial transactions, or trigger external systems. It matches the 'Read' category as a query/analysis operation.
From the tool's definition Tool name 'group_by_length' and description 'Group items by their string length' indicate a data retrieval and organization operation with no side effects.
Attacks that exploit this kind of access
The rule that runs group_by_length 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 group_by_length, this is the rule to start with:
group_by_length 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 group_by_length call is checked against it from then on.
Questions about group_by_length
Group items by their string length. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
group_by_length accepts 1 parameter: items. Required: items. 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 group_by_length: 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.
group_by_length 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 group_by_length 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 group_by_length. 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.
group_by_length 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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