# updateGoogleSheetIfUnchanged Write cell values only if the guarded area has not changed since you read it, and get back what was overwritten so the change can be undone. Call once with dryRun:true to obtain the fingerprint, then again passing it as expectedFingerprint. IMPORTANT: this is optimistic and NOT atomic. The Sheets API has no compare-and-swap - unlike Docs, where ifRevisionId is enforced by the API itself - so the check happens in this server, and a write landing in the gap between the read and the write (well under a second) is not caught. It catches the case that actually happens: the model changed since you last looked. To undo a write, call again with updates set to the returned preImage and expectedFingerprint set to the returned postFingerprint - nothing else, since guardRanges defaults to the ranges in updates and preImage already carries exactly the ranges that were written. Any cell listed in the returned hazards cannot be restored by feeding preImage back: updates carries strings, so re-writing the string re-interprets it as a formula, a number or a boolean and the cell changes type. Its native userEnteredValue is returned so that you can restore that one cell outside this server - through the Sheets API's own updateCells, or by hand - so an undo that touches a hazard cell needs that cell handled separately. The hazard list is deliberately not exhaustive: text kept as text via a leading apostrophe is only flagged when it reads as a formula, a number, or TRUE/FALSE - date-shaped text (e.g. '2024-01-01') is not detected. Agent View of the PolicyLayer registry record for `updateGoogleSheetIfUnchanged`. HTML page: https://policylayer.com/tools/ark7-google-drive-mcp/updategooglesheetifunchanged ## Facts - Tool: `updateGoogleSheetIfUnchanged` - Server: Google Drive (`@ark7/google-drive-mcp`) — https://policylayer.com/tools/ark7-google-drive-mcp.md - Install: `npx -y @ark7/google-drive-mcp` - Homepage: https://www.npmjs.com/package/@ark7/google-drive-mcp - Risk category: Write (Medium risk) - Registry record: grade F, identity unverified - Server rate-limited: no - Parameters: 9 (2 required) - Recommended policy verdict: Rate-limited ## Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | `dryRun` | boolean | no | Write nothing; return the current fingerprint, the guarded contents and what would be written. This is how the first fingerprint is obtained. | | `account` | string | no | Alias of the Google account to target. Optional — defaults to the session/global default account, or the sole authenticated account. Run manage_accounts list to | | `updates` | array | yes | Ranges to write, ValueRange-shaped, same as batchUpdateGoogleSheetValues. Each one must name a bounded rectangle - a single cell, or both corners given as in "S | | `maxBytes` | number | no | Byte budget for the same (default 131072) | | `maxCells` | number | no | Budget for the guarded contents returned on a dryRun or a refusal (default 2000) | | `guardRanges` | array | no | Ranges whose contents must be unchanged. Defaults to the ranges in updates. They need NOT cover the writes - guarding a source block while writing a summary els | | `spreadsheetId` | string | yes | Spreadsheet ID | | `valueInputOption` | string | no | USER_ENTERED (default) parses formulas; RAW stores them as text. SECURITY: USER_ENTERED evaluates formulas, so never use it with untrusted input. | | `expectedFingerprint` | string | no | The fingerprint returned by a previous dryRun call. Required unless dryRun is true. | Parameters from the server's own tool schema. ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "updateGoogleSheetIfUnchanged", "arguments": { "updates": [], "spreadsheetId": "" } } } ``` ## Why updateGoogleSheetIfUnchanged is rated Medium An AI agent can call updateGoogleSheetIfUnchanged faster than any human can review: one bad instruction and it creates or modifies resources in Google Drive by the hundred, each call as confident as the last. Risk signals: High parameter count (11 properties) ## Use case AI agents use updateGoogleSheetIfUnchanged to create or update resources in Google Drive, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Google Drive environment. ## Recommended policy (PolicyLayer) Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Google Drive: ```json { "version": "1", "default": "deny", "tools": { "updateGoogleSheetIfUnchanged": { "limits": [ { "counter": "updategooglesheetifunchanged_rate", "window": "minute", "max": 30, "scope": "grant" } ] } } } ``` ## Other tools on Google Drive (130) - `deleteCalendarEvent` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/deletecalendarevent.md - `deleteComment` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/deletecomment.md - `deleteDimensionGroup` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/deletedimensiongroup.md - `deleteGoogleSlide` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/deletegoogleslide.md - `deleteItem` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/deleteitem.md - `deleteRange` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/deleterange.md - `deleteSheet` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/deletesheet.md - `deleteSlideElement` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/deleteslideelement.md - `removePermission` — Destructive — https://policylayer.com/tools/ark7-google-drive-mcp/removepermission.md - `authGetStatus` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/authgetstatus.md - `authListScopes` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/authlistscopes.md - `authTestFileAccess` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/authtestfileaccess.md - `describeGoogleDocRange` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/describegoogledocrange.md - `downloadFile` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/downloadfile.md - `exportSlideThumbnail` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/exportslidethumbnail.md - `getCalendarEvent` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getcalendarevent.md - `getCalendarEvents` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getcalendarevents.md - `getComment` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getcomment.md - `getDocumentInfo` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getdocumentinfo.md - `getGoogleDocContent` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getgoogledoccontent.md - `getGoogleDocContentPaginated` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getgoogledoccontentpaginated.md - `getGoogleDocImage` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getgoogledocimage.md - `getGoogleDocStyleSummary` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getgoogledocstylesummary.md - `getGoogleSheetCells` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getgooglesheetcells.md - `getGoogleSheetContent` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getgooglesheetcontent.md - `getGoogleSlidesContent` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getgoogleslidescontent.md - `getGoogleSlidesSpeakerNotes` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getgoogleslidesspeakernotes.md - `getRevisions` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getrevisions.md - `getSlideElementInfo` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getslideelementinfo.md - `getSpreadsheetInfo` — Read — https://policylayer.com/tools/ark7-google-drive-mcp/getspreadsheetinfo.md - …and 100 more: https://policylayer.com/tools/ark7-google-drive-mcp.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=ark7-google-drive-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/ark7-google-drive-mcp