numbers_set_header_columns

THE RISK

Medium Risk

Why numbers_set_header_columns needs a policy

This tool modifies document metadata (header column count and styling) in a Numbers spreadsheet. The changes are reversible—header styling can be removed or changed at any time without destroying data. This is a write operation (modification of existing structure) rather than execute (no code/command execution), destructive (no permanent deletion), or other categories.

From the tool's definition Tool description states "Set the number of header columns on a table" and "Set to 0 to remove header column styling" — these are reversible modifications to document formatting/structure within Numbers.

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

POLICY

How to control numbers_set_header_columns

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

policy.json

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

numbers_set_header_columns 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 Iwork — 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 Iwork tools

Destructive keynote_delete_slide Delete a slide from the presentation Destructive numbers_clear_cells Clear the contents of a cell or range Destructive numbers_delete_column Delete one or more columns from a table Destructive numbers_delete_row Delete one or more rows from a table Destructive numbers_delete_sheet Delete a sheet from a Numbers document Destructive numbers_delete_table Delete a table from a sheet Destructive pages_delete_text Delete a paragraph by index (preserves formatting on other paragraphs) Destructive keynote_close_presentation Close a Keynote presentation

All 114 Iwork tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

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 numbers_set_header_columns

What does the numbers_set_header_columns tool do? +

Set the number of header columns on a table. Header columns get special styling. Set to 0 to remove header column styling. It is categorised as a Write tool in the Iwork MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on numbers_set_header_columns? +

Register the Iwork MCP server in PolicyLayer and add a rule for numbers_set_header_columns: 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 Iwork. Nothing to install.

What risk level is numbers_set_header_columns? +

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

Can I rate-limit numbers_set_header_columns? +

Yes. Add a rate_limit block to the numbers_set_header_columns 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 numbers_set_header_columns completely? +

Set action: deny in the PolicyLayer policy for numbers_set_header_columns. 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 numbers_set_header_columns? +

numbers_set_header_columns is provided by the Iwork MCP server (reichenbach/iwork_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Iwork tool call.

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

CHECK YOUR STACK →