Set the width of a table cell in millimetres (stored as DXA).
AI agents use set_cell_width to create or update resources in Docx — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Docx environment.
This tool modifies document formatting by setting a specific cell width property. It is a reversible operation (the width can be changed again or restored), so it falls under Write rather than Destructive. The blast radius is medium because a malicious agent could degrade document readability or layout by setting inappropriate cell widths across a table, but the damage is correctable.
From the tool's definition Tool description states 'Set the width of a table cell' — an explicit modification operation on document structure.
Documented attack patterns abuse exactly the kind of access set_cell_width gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Docx, and nothing reaches the server without passing your rules. This is the rule we recommend for set_cell_width:
{
"version": "1",
"default": "deny",
"tools": {
"set_cell_width": {
"limits": [
{
"counter": "set_cell_width_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}set_cell_width 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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Set the width of a table cell in millimetres (stored as DXA). It is categorised as a Write tool in the Docx MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Docx MCP server in PolicyLayer and add a rule for set_cell_width: 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 Docx. Nothing to install.
set_cell_width 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 set_cell_width 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 set_cell_width. 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.
set_cell_width is provided by the Docx MCP server (securityronin/docx-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Docx, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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219 Docx tools catalogued and risk-classified — across an index of 43,000+ MCP servers.