An agent must call your internal order API with typed arguments. What fits?
Why B is the answer
A custom function tool
Function tools let an agent request calls to your code with structured arguments.
In detail
- A custom function tool defines typed arguments for your API.
- Validate the arguments before the call.
Use case
An illustrative scenario, not a real incident.
An agent must check order status in an internal API. A custom function tool defines typed arguments, and your code calls the API.
See it in different ways
flowchart LR A["Model"] --> D["Agent"] B["Instructions"] --> D C["Tools: file search, web search, code interpreter, MCP, functions"] --> D D --> E["Conversation and actions"]
mindmap
root((Foundry agent))
Definition
Role
Goals
Conversation state
Tools
Code interpreter
Custom functions
Tool schemas
Hosting
Prompt agent
Hosted agent
Control
Human approval
MonitoringsequenceDiagram participant P0 as Agent participant P1 as Your function participant P2 as Order API P0->>P1: Typed arguments P1->>P2: API request P2-->>P1: Status P1-->>P0: Result
Key point: Custom function tools connect your APIs.
Why the other options are wrong
- A. A longer system prompt describing the API
- A description cannot call an API.
- C. A higher temperature
- Temperature has no link to APIs.
- D. A larger search index
- An index searches content, and does not call APIs.