AI agents call get_cell_value to retrieve information from OpenPyXL MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves cell values from an Excel workbook without modifying, executing code, deleting, or affecting finances. The OpenPyXL library's read operations on static files pose minimal risk; data exfiltration is the primary concern, but that is typical of Read operations. Despite empty description, context from sibling tools and server purpose strongly indicates a simple getter.
From the tool's definition Tool name 'get_cell_value' indicates retrieval; sibling tools like 'get_cell_details', 'get_content_of_cell_list', 'get_values_of_cell_range', and 'search_in_cell_range' are all read-only query operations on Excel files.
Documented attack patterns abuse exactly the kind of access get_cell_value gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and OpenPyXL MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_cell_value:
{
"version": "1",
"default": "deny",
"tools": {
"get_cell_value": {}
}
}get_cell_value is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
get_cell_value. It is categorised as a Read tool in the OpenPyXL MCP Server MCP Server, which means it retrieves data without modifying state.
Register the OpenPyXL MCP Server MCP server in PolicyLayer and add a rule for get_cell_value: 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 OpenPyXL MCP Server. Nothing to install.
get_cell_value is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the get_cell_value 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 get_cell_value. 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.
get_cell_value is provided by the OpenPyXL MCP Server MCP server (jonemo/openpyxl-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from OpenPyXL MCP Server, 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.
6 OpenPyXL MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.