Technical interview guide

LLM Agents & Tool Use

Letting an LLM decide which actions to take — calling tools, APIs, or other models — rather than just generating text.

Read: 45 min
Practice MCQs: 25
Interview QA: 25
Edition: v4
Editorial status: Reviewed
Relevant for: AI EngineerAgentic AI EngineerForward Deployed Engineer (FDE)

Scope: ReAct, Toolformer, MRKL, Gorilla, AgentBench, WebArena, SWE-bench, JSON Schema 2020-12, OpenAPI 3.1.1, NIST AI RMF, and OWASP GenAI agent risks reviewed 2026-09-06.

Interview QA

Treat each question like a live interview question: answer out loud first (structure, assumptions, tradeoffs), then open the model answer to spot gaps and rehearse a tighter follow-up.

Curated: 2026-10-05 · Written: 2026-10-05 · Reviewed: 2026-10-03

QA-1

Design the trust boundary of an LLM agent.

QA-2

Design a production-grade tool contract.

QA-3

Authorize an agent's resource mutation.

QA-4

Validate model-generated tool arguments safely.

QA-5

Contain malicious instructions in tool results.

QA-6

Design agent budgets and loop termination.

QA-7

Define completion for a multi-step agent workflow.

QA-8

Design retries for a payment or message-send tool.

QA-9

Implement tamper-resistant approval for tool actions.

QA-10

How do you design communication and state handoff in hierarchical multi-agent architectures (orchestrator-workers vs peer routing)?

QA-11

Provision credentials for an agent task.

QA-12

Sandbox agent-generated code safely.

QA-13

Design safe parallel execution in an agent plan.

QA-14

Design secure multi-agent delegation.

QA-15

Design agent memory governance.

QA-16

Implement cancellation for a long-running agent workflow.

QA-17

Design tool error and retry semantics.

QA-18

Design tamper-evident agent auditing.

QA-19

Build an agent evaluation harness.

QA-20

Translate agent benchmarks into release gates.

QA-21

Red-team an agent against prompt injection.

QA-22

Detect and recover from agent no-progress behavior.

QA-23

Design agent production observability.

QA-24

Design emergency containment and rollback for an agent platform.

QA-25