AI agents call hmac_md5 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 |
|---|---|---|---|
key | string | Yes | Secret key |
message | string | Yes | Message to authenticate |
Parameters from the server's own tool schema.
HMAC-MD5 is a deterministic hashing function used for data validation, integrity checking, and authentication. It produces output based on input parameters but does not read sensitive data, modify state, execute arbitrary code, delete data, or move money. The tool is part of a suite of deterministic utility functions for AI agents (math, conversion, validation, hashing, encoding).
From the tool's definition Tool name 'hmac_md5' and description 'Generate HMAC-MD5' indicate a cryptographic hash generation function that computes a fixed output from inputs without side effects or state modification.
Attacks that exploit this kind of access
Generate HMAC-MD5. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
hmac_md5 accepts 2 parameters: key, message. Required: key, 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 hmac_md5: 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.
hmac_md5 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 hmac_md5 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 hmac_md5. 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.
hmac_md5 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.
hmac_md5 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.
Teams ship this data inside their own products. See what a licence covers →