Practice — Tool and Function Calling (9 questions)

Your team shipped an internal assistant with one tool:

{
  "name": "manage_ticket",
  "description": "Handles ticket operations",
  "parameters": {
    "type": "object",
    "properties": {
      "action": { "type": "string" },
      "data": { "type": "object" }
    },
    "required": ["action"]
  }
}

In evaluation, the model regularly calls it with the wrong action string (e.g. "update" when it meant "close"), and data comes back shaped differently every time, which breaks the handler that parses it.

1. Explain why this tool's shape is causing exactly these two failure modes.
2. Redesign it — show the new tool definition(s).
3. What would you check in evaluation to confirm the redesign actually fixed tool-selection accuracy, not just made the schema prettier?

A tool definition sent to the model has three parts: a name, a description, and a JSON-schema parameters object. The model reads all three at inference time before deciding whether to call the tool and, if so, with what arguments — it never sees your source code or your internal docs.

What is the primary role the description field plays in that process?