Three tools. Safe inputs. Focused output.

render_chart

Use for quantitative stories: ranking, comparison, trends, composition, contribution, before/after, ranges, and relationships.

{
  "type": "bar",
  "insight": "Enterprise is the growth engine",
  "title": "Net retention by segment",
  "data": [
    { "segment": "Enterprise", "retention": 1.18 },
    { "segment": "SMB", "retention": 0.96 }
  ],
  "encoding": { "category": "segment", "value": "retention" },
  "options": { "percent": true, "showValues": true }
}

render_diagram

Use for explicit structure: processes, systems, sequences, state transitions, entity relationships, timelines, and conceptual maps. Mermaid runs with strict security settings.

{
  "insight": "The decision path has three gates",
  "mermaid": "flowchart LR\n A[Input] --> B[Decision] --> C[Outcome]"
}

render_network

Use for relationships that are too dense or exploratory for a hand-authored diagram. Layout, pan, zoom, fit, selection, and highlight behavior are client-side.

{
  "title": "Service dependencies",
  "nodes": [{ "id": "api", "label": "API" }],
  "edges": [{ "source": "api", "target": "db" }],
  "layout": "dagre"
}