This record as markdown: /tools/io-tinyfn-tinyfn/echo.md
What echo does on TinyFn
AI agents call echo 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 |
|---|---|---|---|
message | string | Yes | Message to echo back |
Parameters from the server's own tool schema.
Why echo is rated Low
The echo tool merely reflects input back to the caller with no side effects, data modification, code execution, or irreversible actions. It is purely informational, suitable for testing connectivity or tool availability. This is a benign Read operation with negligible blast radius if misused by an AI agent.
From the tool's definition Tool name and description: 'Echo back the message. For testing.' This is a simple utility function that returns input without modification or side effects.
Attacks that exploit this kind of access
The rule that runs echo 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 echo, this is the rule to start with:
echo 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 echo call is checked against it from then on.
Questions about echo
Echo back the message. For testing. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
echo accepts 1 parameter: message. Required: message. 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 echo: 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.
echo 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 echo 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 echo. 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.
echo 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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