A charting tool that returns a URL rather than an image is a reasonable design — ECharts is interactive, and a link preserves the hover and zoom a flattened PNG loses. What makes it work is saying so on every tool, because a model that assumes it received an image will describe one that does not exist and hand the user a broken reference. Splitting by chart type rather than taking a type parameter is the other useful choice: each tool's description says what its chart is for, which helps a model pick the right visualisation rather than defaulting to bar.
An ECharts chart generator that returns preview links rather than images: six dedicated chart types and one general tool covering the others.
- Dedicated tools for bar, line, pie, heatmap, radar and scatter, each stating what its chart type is for — scatter for the relationship between two variables, radar for multidimensional comparison, heatmap for density.
- generate_general_chart covers the types without their own tool.
- Every tool states in its own description that it returns a preview link and not a chart image, so the output is a URL to open rather than something to embed directly.
Nothing to supply.
One command — npx -y echarts-mcp-server