AI agents use excel_create_sheet to create or update resources in Excel — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Excel environment.
Creating a new worksheet is a reversible modification operation that adds data/structure to an Excel file without permanently destroying data or executing arbitrary code. This fits the Write category. Severity is medium because while the operation is reversible, it can affect multiple dependent sheets and game configurations if the workbook is structured with interdependencies.
From the tool's definition Tool name 'excel_create_sheet' and description '创建新的工作表' (create new worksheet) indicate the creation of a new sheet, which modifies the workbook structure reversibly.
Documented attack patterns abuse exactly the kind of access excel_create_sheet gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Excel, and nothing reaches the server without passing your rules. This is the rule we recommend for excel_create_sheet:
{
"version": "1",
"default": "deny",
"tools": {
"excel_create_sheet": {
"limits": [
{
"counter": "excel_create_sheet_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}excel_create_sheet 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.
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创建新的工作表. It is categorised as a Write tool in the Excel MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Excel MCP server in PolicyLayer and add a rule for excel_create_sheet: 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 Excel. Nothing to install.
excel_create_sheet is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the excel_create_sheet 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.
Set action: deny in the PolicyLayer policy for excel_create_sheet. 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.
excel_create_sheet is provided by the Excel MCP server (tangentdomain/excel-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Excel, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
36 Excel tools catalogued and risk-classified — across an index of 43,000+ MCP servers.