Key answer
Clarity depends on whether unstated details could lead to an unacceptable result. There is no fixed length or requirement that every sentence contain a subject, verb and object. “Translate the following into English” specifies action and object; “make me a plan” leaves purpose, audience and tradeoffs open.
Full explanation
AmbigQA's analysis of 14,042 open-domain questions found multiple reasonable interpretations in over half, including ambiguous events and entities. That proportion belongs to the dataset, not all everyday questions; even a grammatically complete sentence can lack information needed for a determinate answer. Study
To assess background, ask: Would changing this detail change the answer I expect? “The readers are students new to AI” affects explanatory depth. “I am writing in a coffee shop today” usually does not, unless the setting is part of the writing task. This is a selection heuristic, not the sole experimentally established rule.
More background is not always better. Shi et al. added irrelevant information that did not change the answers to GSM-IC math questions and observed reduced performance. This supports removing distractions, not claiming that every longer prompt is worse. Study
Start with:
Explain “context window” to readers new to AI for an introductory webpage, in about 200 words. Cover its effects rather than formulas and include one everyday example.
If unsure, ask AI which missing details would produce substantially different versions. Google's documentation allows questions, tasks, objects to process and partial inputs; it does not require one fixed sentence template. Official documentation
References
1. Min et al. (2020), AmbigQA: Answering Ambiguous Open-domain Questions, EMNLP
2. Shi et al. (2023), Large Language Models Can Be Easily Distracted by Irrelevant Context, ICML
3. Google, Prompt design strategies, official Gemini developer documentation