render_native_sheet_cell_explanation

Render a read-only derivation explanation for one cell of an output sheet view: a DAG of same-sheet formula precedents plus a plain-language summary/narrative/confidence explanation. Only explains output sheet view cells (purpose=‘output’); input sheets are rejected. Call list_native_sheets/get_native_sheet first to find a valid sheet_id/tab_id/cell_ref.

Parameters

Name	Type	Required	Default	Description
`model_name`	`Annotated[str, Field(description='Name of the Bridge Town model that owns the sheet.')]`	Yes	—
`sheet_id`	`Annotated[str, Field(description="Sheet identifier, as returned by list_native_sheets. Must be an output sheet view (purpose='output'); input sheets are rejected.")]`	Yes	—
`tab_id`	`Annotated[str, Field(description='Tab to explain a cell on, as returned by get_native_sheet.')]`	Yes	—
`cell_ref`	`Annotated[str, Field(description="A1 cell reference to explain, e.g. 'B7'.")]`	Yes	—
`branch`	`Annotated[str	None, Field(description=“Branch whose cached row to read. Omit to read the model’s default-branch row.”)]`	No	`None`

Returns

Returns a structured object. Top-level fields:

schema_version (integer)
cell_ref (string)
selected_value_summary (string)
narrative (string)
confidence_note (string)
overall_evidence_quality (string)
provenance (object)
nodes (array<object>)
edges (array<object>)
selected_node_id (string)

See the response example below for the full payload shape.

Example

Tool Call

{
  "name": "render_native_sheet_cell_explanation",
  "arguments": {
    "model_name": "forecasts",
    "sheet_id": "q1-output",
    "tab_id": "tab1",
    "cell_ref": "B1"
  }
}

Response

{
  "schema_version": 1,
  "cell_ref": "Summary!B1",
  "selected_value_summary": "B1 = 1800000",
  "narrative": "B1 is computed by the formula '=A1*2' on the 'Summary' tab, which depends on: Summary!A1.",
  "confidence_note": "Evidence is derived directly from this sheet's own formulas and recorded values; lineage across other models, runs, or branches is not covered here.",
  "overall_evidence_quality": "exact",
  "provenance": {
    "source": "run",
    "run_id": "66666666-6666-6666-6666-666666666666",
    "commit_sha": "abc1234def5678901234567890abcdef12345678",
    "branch": "main",
    "output_name": "revenue_by_quarter",
    "data_hash": null
  },
  "nodes": [
    {
      "id": "Summary!B1",
      "type": "output",
      "label": "=A1*2",
      "status": "ok",
      "evidence_quality": "exact",
      "value": "1800000",
      "detail": "=A1*2",
      "ref": "B1",
      "provenance": null
    },
    {
      "id": "Summary!A1",
      "type": "run_output",
      "label": "Summary!A1",
      "status": "ok",
      "evidence_quality": "exact",
      "value": "900000",
      "detail": null,
      "ref": "A1",
      "provenance": null
    }
  ],
  "edges": [
    {
      "id": "e0",
      "source": "Summary!A1",
      "target": "Summary!B1",
      "evidence_quality": "exact",
      "label": null
    }
  ],
  "selected_node_id": "Summary!B1"
}

Notes

Module: Native Sheets
Requires authentication via API token or Auth0 JWT.