MCP Changes

Changes to the tools, their arguments and the outline, newest first. A change that alters a shape an agent may already read says what to check.

October 2026: how cards read and show

• Card settings in a change. card.add and card.update take columns (each column's label, format, hidden and width), totals, dataLabels, legend and axes, and a chart's variant as orientation, stack and donut. See How Cards Read and Show.
• Highlights. highlight.add and highlight.remove color cells and rows where a condition holds, shade a column on a color scale, or add data bars.
• The dashboard's title and description. dashboard.update. The outline shows the description.
• The outline shows each editable card's settings, with inherits and editorOnly.
• The server's instructions give one recipe: read the outline, change only what the user asked, propose, and apply when confirm is not_needed or the user agrees. The tool definition lists a format's stored fields, and a refused format's fix states them.
• confirm on every proposal: not_needed when a proposal only changes how cards read and show, or the dashboard's title and description; needed otherwise. An apply checks again and refuses with confirm_changed when that has changed.
• Horizontal bars, stacked bars, stacked lines and areas and doughnuts can be changed.

Check in your code: the outline's type for those five variants is now the base type with the variant as properties. A stacked bar that read "type": "stacked_bar" now reads "type": "bar", "orientation": "vertical", "stack": "stacked", and a doughnut reads "type": "pie", "donut": true. Bar, line, area and pie cards carry their properties too.