Important terms

TermEasy meaning
Prompt engineeringDesigning prompts so the model works reliably, not just “asking nicely”.
Structured outputA response in a strict shape, often JSON, that software can safely parse.
Reasoning effort / thinking levelHow much internal thinking compute the model uses before answering.
GroundingUsing search, retrieved docs, or tools so answers are based on evidence.
RAGRetrieval-Augmented Generation. Search relevant documents and give them to the model.
Prompt injectionWhen untrusted text tries to act like instructions and hijack the model.
Planner–executorOne step or model plans; another step or model executes the work.
Evaluation flywheelAnalyze failures, measure them, improve prompts, test again.
Lost in the middleImportant facts in the middle of a long prompt are easier to miss.
Thought signaturesGemini mechanism for preserving reasoning context in some flows.
Done criteriaClear definition of what finished, correct work looks like.