This record as markdown: /tools/io-tinyfn-tinyfn/sum-digits.md
What sum_digits does on TinyFn
AI agents call sum_digits 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 | integer | Yes | Number to sum digits of |
Parameters from the server's own tool schema.
Why sum_digits is rated Low
This is a pure computational utility that reads an input number and returns a calculated result. It retrieves/computes a value deterministically without creating, modifying, deleting data or triggering external operations. It poses minimal risk even if misused by an AI agent.
From the tool's definition Tool performs a mathematical computation on its input (sum the digits of a number) with no side effects, no data modification, and no external operations.
Attacks that exploit this kind of access
The rule that runs sum_digits 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 sum_digits, this is the rule to start with:
sum_digits 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 sum_digits call is checked against it from then on.
Questions about sum_digits
Sum the digits of a number. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
sum_digits 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 sum_digits: 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.
sum_digits 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 sum_digits 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 sum_digits. 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.
sum_digits 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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