Every Tool Parameter Is a Question Your Voice Agent Has to Ask
If you have ever designed a REST endpoint, you already know most of what it takes to give a voice agent tools. Name it well, keep the parameters tight, validate inputs, return something useful. The difference is the client. Your endpoint is not called by a frontend developer reading your docs. It is called by a language model that is taking dictation from a stranger on a phone line, in real time,…
Voice agents require careful design of tool parameters, much like REST endpoints. The key differences are the client (an LLM taking dictation from a caller) and the real-time, silent nature of the interaction. Retell AI tools follow two shapes: one with detailed schema and infrastructure IDs, and another with parameters that callers would naturally provide.
The latter shape is more effective, as it avoids unnecessary data from the model and focuses on what the caller can actually say. Every required parameter should be a question the agent asks, with server-side resolution of business logic.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
