Write values to a cell range in a worksheet. Values are a 2D array where each inner array is a row.
AI agents use excel_write_range to create or update resources in Sage MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Sage MCP environment.
This tool modifies data in Excel spreadsheets by writing values to cell ranges. It is categorized as Write rather than Destructive because the changes are reversible—existing values can be overwritten or changes undone. Severity is medium because an AI agent with access could modify important spreadsheet data, but the impact is contained to the affected cells and reversible.
From the tool's definition Tool name 'excel_write_range' and description 'Write values to a cell range in a worksheet' explicitly indicate data modification. The operation modifies spreadsheet cells but is reversible (can be undone or overwritten).
Documented attack patterns abuse exactly the kind of access excel_write_range gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Sage MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for excel_write_range:
{
"version": "1",
"default": "deny",
"tools": {
"excel_write_range": {
"limits": [
{
"counter": "excel_write_range_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}excel_write_range 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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Write values to a cell range in a worksheet. Values are a 2D array where each inner array is a row. It is categorised as a Write tool in the Sage MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Sage MCP server in PolicyLayer and add a rule for excel_write_range: 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 Sage MCP. Nothing to install.
excel_write_range 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_write_range 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_write_range. 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_write_range is provided by the Sage MCP server (sagemcp/sagemcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 359 Sage MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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359 Sage MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.