Power BI toolkit

Prep for AI Writer

Write the AI instructions, synonyms and table and column descriptions that help Copilot in Power BI give your report users better answers.

Step1

Export your model from Power BI Desktop

The same query the other toolkit pages use. If you already ran it, paste those results in Step 2.

Open your report in Power BI Desktop and select DAX query view on the left rail.
Paste the query below into a new query tab and select Run.
Above the results grid, select Copy. It copies every row with the column headers.

DAX query

Step2

Paste the results and check readiness

These checks run without AI. They show what Copilot has to work with, and the names most likely to confuse it.

Step3

Tell Copilot about the business

Everything here is optional, but specific answers make much better instructions. Copilot is told not to invent facts, and to mark guesses with CHECK: for you to confirm.

What does this model cover? The business, the process, what a row of the main table is. Who asks the questions? Roles and what they care about. Fiscal year starts in Default period When a question doesn't say.

Most important measures Copilot should prefer these.

Lower is better for Costs, turnover, error rates.

Words your team uses One per line: what people say = what it means in the model. Fields to avoid and data caveats Known gaps, test data, fields that look right but aren't. Anything else

Tables Copilot should know about

Hidden tables are left out. Clear helper and technical tables so the prompt stays focused.

Step4

Copy the prompt into Copilot

Copilot answers with the instructions and a synonyms list inside one code block.

Prompt for Copilot

The last line is === END OF PROMPT ===. If Copilot's input box doesn't show it, clear some tables in Step 3.

Step5

Paste the reply, edit, and add it to the model

Use the Copy button on Copilot's code block. Pasting a new reply replaces the previous one; your edits below are kept until you paste again.

AI instructions Edit freely. Replace or delete every CHECK: line before you publish.

Synonyms

Add a Synonyms section to the instructions

Include	Field	Synonyms (comma separated)	Status

AI instructions to paste

Add it to the model

In Power BI Desktop, select Prep data for AI on the Home ribbon (in the service, it's on the semantic model's ribbon).
Open the Add AI instructions tab, paste, and select Apply.
In Desktop, close and reopen the Copilot pane so it picks up the new instructions, then ask it a few real questions to test.
Optional: for the fields that matter most, also paste their synonyms into Model view > Properties > Synonyms. Copy synonyms as table gives you the list.

Step3

Choose tables and copy the prompt

Copilot uses table and column descriptions when it searches the model and writes DAX. Measures are covered by the Measure Describer.

Include hidden columns Rewrite existing descriptions

Items per prompt

Prompt for Copilot

Paste the prompt into Copilot, then paste the reply in Step 4. The prompt moves on to the next items by itself; repeat until the bar is full.

Step4

Paste Copilot's reply and review

Each reply is added to the review below and the box clears for the next one.

Review

Unticked rows are left out. Ask again puts an item back in the next prompt.

Apply	Table or column	Description	Status