Microsoft Excel Runtime Skill

Use this skill to read and edit the user's Excel workbooks through the Excel MCP (mcp__ms_excel__*), backed by Microsoft Graph. Every call targets a workbook by file_id (the OneDrive/SharePoint item id).

When To Use

Use Excel when the user asks to read or change spreadsheet data, append rows to a table, add/rename worksheets, work with named ranges, or recalculate a workbook. To find the workbook's file_id first, use mcp_onedrive (search_files).

Connection

Authenticates via Microsoft OAuth. On an auth/scope error, stop and ask the user to reconnect. You need the workbook file_id up front — resolve it via OneDrive search if the user names a file.

Core Tools

Worksheets:

• list_worksheets (req file_id), add_worksheet, rename_worksheet (req …,worksheet,new_name), delete_worksheet (req …,worksheet).

Cells / ranges:

• read_range (req file_id,worksheet,address — A1 like A1:D20), read_used_range (all populated cells on a sheet).
• write_range (req …,address,values — a 2D array), update_cell (single cell convenience), clear_range (req …,address).

Tables (structured):

• list_tables, get_table_rows (req …,table), add_table_rows (req …,table,values — append), create_table (promote a range, req …,worksheet,address).

Other:

• calculate (recalc, req file_id), list_named_items, get_named_item_range (req …,name).

Common Recipes

Read a region

1. list_worksheets to confirm the sheet name. 2. read_range with an A1 address, or read_used_range to grab everything populated.

Append rows to a table

1. list_tables → the table name. 2. Confirm the rows with the user. 3. add_table_rows with a 2D values array (matching the table's columns).

Bulk-write data

1. read_range/read_used_range to understand current layout. 2. Confirm the target address won't clobber needed data. 3. write_range with a 2D values array. 4. calculate if formulas depend on the new values.

Guardrails

• write_range, update_cell, and clear_range overwrite existing cells in place — there is no undo here. Read the target range first, confirm the exact address, and never write to a wider range than needed.
• values must be a 2D array whose shape matches the target range / table columns — a shape mismatch silently writes the wrong cells. State the shape before writing.
• delete_worksheet / clear_range are destructive — confirm first; prefer appending (add_table_rows) over overwriting.
• After writing values that feed formulas, run calculate so reads reflect the recalculated result.

Edge Cases & Errors

• address is A1 notation (Sheet-scoped via the worksheet arg) — don't include the sheet name in the address.
• read_used_range can be large on big sheets — prefer a bounded read_range when you know the region.
• Table appends must match the table's column count/order; read get_table_rows once to learn the schema.
• Auth/scope errors → stop and ask the user to reconnect.