CCDV-F Agents and the Agent SDK Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Wrapping the refund tool in a retry loop that re-invokes the model until the operator approves in a separate chat window.

  Why it's wrong here

  Re-invoking the model starts or continues a generation, but a retry loop has no notion of a suspended session or an out-of-band approval channel. It wastes tokens, can duplicate side effects, and cannot inject the operator's decision as a first-class conversation event, so the agent cannot reliably resume the identical paused execution.

• ✗

  A custom tool whose handler blocks on stdin and returns the operator's typed answer as a tool_result.

  Why it's wrong here

  Blocking a tool handler on interactive stdin stalls the agent process and cannot resume a previously serialized session; the operator may not even be attached to the same host. It also bypasses the SDK's structured pause and resume semantics, so conversation state and pending tool calls are not durably preserved across the approval window.

• ✗

  Increasing max_tokens and instructing the model in the system prompt to ask for confirmation before calling the refund tool.

  Why it's wrong here

  A prompt instruction only nudges model behavior and provides no enforcement mechanism; the model can still emit the refund tool call directly. Raising max_tokens merely allows longer outputs. Neither feature pauses execution, captures an external decision, or restores a suspended session, so the approval guarantee the scenario requires is absent.

• ✓

  Permission callbacks combined with session persistence, so the agent suspends on the sensitive action and later resumes from the saved session state.

  Why this is correct

  Permission callbacks let the SDK intercept a sensitive tool invocation and hand the decision to your code before execution, while session persistence saves the full conversation and pending state. Resuming the same session with the operator's decision injected as a new message continues the run exactly where it paused, which is the intended approval pattern.