Senior interview question
Where does an agent's reliability come from?
Model answer
Mostly the harness: the code that defines the tools, validates and runs calls, handles failures, manages the context, enforces limits and records everything.
Scroll sideways to see the whole diagram
The model makes the judgment calls, one step at a time, from what's in its context.
Text version
- The model makes the judgment calls, one step at a time, from what's in its context.
- Everything else is ordinary software around it: the harness. This module is mostly about that column, because it's where reliability comes from.
A prompt makes a mistake rarer; a check in code makes it impossible. Anthropic's principles point the same way: keep it simple, make planning visible, and design the agent-computer interface carefully.
Practise the rest
6 Agent loop questions, 492 in all, each with a model answer. Free.