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What is a prompt

Also known as: AI prompt, AI instructions

Definition

A prompt is the instruction you give an AI tool: the question, the task, the context and the format you want. A clearer prompt gets a more useful answer.

Why it matters

The prompt is the one part of an AI tool you control completely.

Common mistakes

Writing one vague line and expecting the tool to guess the format, the tone and the facts you need.

Related terms

Worked exampleIllustration

A prompt for price questions on WhatsApp, at a fictional pilates studio

Role

You answer WhatsApp messages for a small pilates studio, in friendly, short Hebrew.

Task

Reply to a question about prices and trial classes.

Context

Use only the attached price list and schedule. If something is not in them, say you will check and get back.

Format

At most three short lines, no emojis, end with one question that invites booking a trial.

Example

  • A trial class is [from the price list]. A monthly card is [from the price list]. Would you like to try a class this week?

What each part did

  1. Role The answer came out short, friendly and in Hebrew.

  2. Task It answered the question about prices and trial classes, and nothing else.

  3. Decision: Context It took every amount from the attached price list and did not invent a discount, because the context forbade it.

  4. Format Three short lines, no emojis, ending with a question that invites a trial class.

  5. Example It followed the shape of the sample reply.

Role, task, context, format, example. Five lines turned a generic answer into one you could send after a quick check.

Illustration

Switch a part off, watch the reply change

The assistant’s sample reply

Hi, thanks for asking! A trial class is [from the price list].

A monthly card is [from the price list].

Would you like to try a class this week?

  • Short and friendly, like the studio
  • Only prices and trial classes
  • Amounts left to the price list
  • Three short lines, ends with a question
  • Same shape as the sample reply

All five parts on: a short, friendly reply that leaves every amount to the price list, ready to send after a quick check. Switch a part off to see what it was doing.

Each part of the prompt does one job. Switch one off and the sample reply loses what that part was doing. Every amount stays in the price list.

Definition

A prompt is everything you write to an AI tool to get a result: a question, a task, the background it needs, the shape the answer should take, and sometimes an example. Chat tools also keep a standing instruction that applies to every conversation, often in a box called custom instructions or project instructions. Developers call that the system prompt, and the message you type each time the user prompt. A good prompt usually has five parts: a role, a task, context, a format and an example. You write it in plain language, including Hebrew.

Why it matters

The same model gives a generic answer to a vague prompt and a usable one to a clear prompt. Clear context also limits what the tool can invent: "use only the attached price list" leaves it far less room to guess prices.

Directly related: LLM, Hallucination, Context Window.

Improvement tips

  • When the result matters, write all five parts: role, task, context, format and one example of a good answer.
  • Separate your instructions from the text you paste, for example with a line or a heading, so the tool knows which is which.
  • Say what to do when the answer is missing: "if it is not in the attached file, say you will check".
  • Save the prompts that worked in one shared document, so the whole team gets the same result.

Common mistakes

  • Packing several unrelated tasks into one prompt instead of one prompt per task.
  • Pasting customer ID numbers, medical details or card details into a public AI tool.
  • Letting a tool that can send email or change files act on instructions without a person's approval.

Related terms

AI and DataIntermediate

LLM

An LLM (large language model) is AI trained on masses of text to predict the next piece of a sentence. That is how chat tools write answers, right or wrong.

AI and DataBeginner

Hallucination

An AI hallucination is an answer an AI model makes up and states with confidence, such as an invented price, rule or source, because it predicts likely words.

AI and DataIntermediate

Context Window

A context window is how much text, in tokens, a model can see at once: instructions, files, the chat so far and its reply. What falls outside, it cannot use.

AI and DataIntermediate

Token

A token is a piece of a word that an AI language model reads and writes. Usage is counted and billed in tokens, and the same text takes more in some languages.

AI and DataAdvanced

RAG

RAG (retrieval-augmented generation) is a method where AI answers from your documents: it first finds the relevant passages, then writes the answer from them.

AI and DataAdvanced

Agent

An AI agent is AI software that does tasks, not just answers: it plans steps and uses connected tools, such as a calendar or email, to reach a goal you set.

Quick check

Which line of a prompt stops a WhatsApp assistant from inventing a discount?

Choose an answer

Frequently asked questions

What is a prompt in simple words?
The instruction you give an AI tool: what you want, with what background and in what shape. It can be one question or a full page of instructions. The tool answers what the prompt asks, so a clearer prompt gets a more useful answer.
How do I write a good prompt?
Use five parts. Role: who is writing, for example "a friendly assistant of a small studio". Task: what to do. Context: the facts and files to use, and what to do when something is missing. Format: length, tone and structure. Example: one sample of a good answer. The prompting guides of Anthropic, Google and OpenAI all advise a clear task, context, examples and keeping instructions apart from the material.
Can I write prompts in Hebrew?
Yes. You can write the prompt in Hebrew and get the answer in Hebrew. If the wording matters, say so in the format part, for example "natural Hebrew, not translated".
What is a system prompt?
A standing instruction that applies to every message in a tool or a conversation, written once instead of repeated. In chat tools you meet it as the custom instructions or project instructions box. What you type in each message is the user prompt.
Is writing prompts a kind of programming?
No. You write in plain language, including Hebrew, and describe what you want. What makes a prompt work is what makes a brief to a new employee work: a clear task, the facts and an example.
Why does the AI ignore part of my instructions?
Usually because the prompt mixes several tasks, or the instructions and the pasted text run together. Give one task per prompt, separate the instructions from the material with a line or a heading, and put the most important rule where it cannot be missed.
How do I stop the tool inventing facts?
Give it the facts and limit it to them: "use only the attached price list and schedule, and if something is not in them, say you will check". That reduces invented answers, it does not end them, so a person still checks anything that reaches a customer.
Can a prompt harm my computer or my files?
In a plain chat, no: the tool only writes text. It changes when the tool can act, for example send email, book appointments or edit files. Then instructions can trigger actions, and instructions hidden in a web page or a document the tool reads can steer it. OWASP ranks this, prompt injection, first in its 2025 list of risks for such applications. In a tool that can act, keep a person's approval before anything is sent or changed.
What should I never paste into a prompt?
Never paste customer ID numbers, medical details, card details or anything you would not send by email to a stranger into a public AI tool. Israel's Privacy Protection Law, 1981, as amended by Amendment 13, in force since 14 August 2025, governs collecting, keeping and using personal details, including details you paste into or upload to an AI tool. Educational material, not legal or tax advice. Check your own case with a lawyer or an accountant.
Do I need to buy prompt templates?
No. A template is a starting point, not a result: the useful part of a prompt is your own context, facts, tone and example. Adapt any template to your business before you rely on it.
How long should a prompt be?
As long as the task needs. A quick question needs one line. A prompt that will answer customers for months deserves all five parts and a sample answer. Everything in the prompt is read on every run, so leave out what the task does not use.
Should the team share prompts?
Yes. Keep the prompts that worked in one shared document, with a line on what each is for, so everyone gets the same quality and nobody starts from scratch. Update it when a prompt stops giving good answers.

Sources: Anthropic, "Prompting best practices", Claude documentation (platform.claude.com/docs/en/build-with-claude/prompt-engineering), read 2026-09-25, OpenAI, "Prompt engineering" guide, API documentation (developers.openai.com/api/docs/guides/prompt-engineering), read 2026-09-25, Google, "Prompt design strategies", Gemini API documentation (ai.google.dev/gemini-api/docs/prompting-strategies), read 2026-09-25, OWASP, Top 10 for LLM Applications 2025, LLM01:2025 Prompt Injection (genai.owasp.org/llmrisk/llm01-prompt-injection), read 2026-09-25, Privacy Protection Authority, Amendment 13 questions and answers (gov.il/he/pages/tikun13_qa), read 2026-08-31

Last reviewed: 2026-09-25

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