Replace data series in an existing chart by chart_id.
AI agents use update_chart_data 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 creates or modifies data reversibly within a Word document—it updates chart data but does not delete the chart or data irreversibly. The modification is contained to the chart's data series and can be undone (Word tracks changes and maintains undo history). This is a write operation rather than destructive because it modifies rather than deletes, and the document remains intact.
From the tool's definition The tool 'update_chart_data' replaces data series in an existing chart by chart_id. The verb 'replace' and the action of modifying chart data indicates a write operation that modifies document content.
Documented attack patterns abuse exactly the kind of access update_chart_data 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 update_chart_data:
{
"version": "1",
"default": "deny",
"tools": {
"update_chart_data": {
"limits": [
{
"counter": "update_chart_data_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}update_chart_data 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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Replace data series in an existing chart by chart_id. 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 update_chart_data: 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.
update_chart_data 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 update_chart_data 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 update_chart_data. 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.
update_chart_data 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.