addColumns

THE RISK

Medium Risk

Why addColumns needs a policy

This tool creates/modifies spreadsheet structure by inserting columns, which is reversible (columns can be deleted). It does not execute arbitrary code, delete data irreversibly, or involve financial transactions. The blast radius is moderate—accidental column additions could disrupt data organization but are easily undone. This is a Write operation that modifies sheet metadata/structure.

From the tool's definition The tool 'addColumns' accepts arguments to add columns to a sheet: spreadsheetId, sheetname, count of columns, and startColumn. The description explicitly states it 'Adds the specified number of columns', which modifies the sheet structure.

Documented attack patterns abuse exactly the kind of access addColumns gives an agent:

POLICY

How to control addColumns

PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Google Sheets, and nothing reaches the server without passing your rules. This is the rule we recommend for addColumns:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "addColumns": {
      "limits": [
        {
          "counter": "addcolumns_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

addColumns stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

Create a free account and register Mcp Google Sheets — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Mcp Google Sheets tools

Write addRows Adds the specified number of rows to the specified sheet. Accepts spreadsheetId, sheetname Write batchUpdate Updates a range of values using the batchUpdate function of google sheets. The ranges are Write copySheet Copies the contents of the source sheet to destination sheet. Accepts srcSpreadsheet, srcS Write create Creates a spreadsheet by taking the new sheet Write createSheet Creates a new sheet in the spreadsheet provided as an argument. Accepts spreadsheet id and Write renameSheet Renames the provided sheet. Accepts spreadsheet id, old name and new name of the sheet as Write shareSpreadsheet Shares the provided spreadsheet to the recipients provided as an argument. Accepts recipie Write updateCells Updates the values present in the cells specified in the given range for the provided shee

All 13 Mcp Google Sheets tools →

Write tools on other servers

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Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about addColumns

What does the addColumns tool do? +

Adds the specified number of columns to the specified sheet. Accepts spreadsheetId, sheetname, count of columns to be added, startColumn as arguments. It is categorised as a Write tool in the Mcp Google Sheets MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on addColumns? +

Register the Mcp Google Sheets MCP server in PolicyLayer and add a rule for addColumns: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Mcp Google Sheets. Nothing to install.

What risk level is addColumns? +

addColumns is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit addColumns? +

Yes. Add a rate_limit block to the addColumns rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block addColumns completely? +

Set action: deny in the PolicyLayer policy for addColumns. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides addColumns? +

addColumns is provided by the Mcp Google Sheets MCP server (rohans2/mcp-google-sheets). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mcp Google Sheets tool call.

Start from Mcp Google Sheets, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →