Insert a native bar chart (no Excel required).
AI agents use insert_bar_chart 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 adds a new chart object to a Word document, modifying the document's content in a reversible manner. This is a Write operation—it does not execute arbitrary code, delete data, or move money. The severity is medium because uncontrolled chart insertion could degrade document integrity or consume resources, but the operation is reversible through undo or deletion.
From the tool's definition Tool name 'insert_bar_chart' and description 'Insert a native bar chart' indicate creation of new content within the document.
Documented attack patterns abuse exactly the kind of access insert_bar_chart 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 insert_bar_chart:
{
"version": "1",
"default": "deny",
"tools": {
"insert_bar_chart": {
"limits": [
{
"counter": "insert_bar_chart_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}insert_bar_chart 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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Insert a native bar chart (no Excel required). 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 insert_bar_chart: 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.
insert_bar_chart 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 insert_bar_chart 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 insert_bar_chart. 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.
insert_bar_chart 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.
Free to start. No card required.
219 Docx tools catalogued and risk-classified — across an index of 43,000+ MCP servers.