Get historical events that occurred on a specific date
AI agents call onThisDay to retrieve information from Wikipedia MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves historical event information from Wikipedia based on a date parameter. It performs a read-only operation with no side effects—it neither modifies data, executes code, deletes content, nor commits financial obligations.
From the tool's definition Tool name 'onThisDay' and description 'Get historical events that occurred on a specific date' indicate data retrieval with no modification, deletion, or execution of external operations.
Attacks that exploit this kind of access
Get historical events that occurred on a specific date. It is categorised as a Read tool in the Wikipedia MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Wikipedia MCP Server MCP server in PolicyLayer and add a rule for onThisDay: 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 Wikipedia MCP Server. Nothing to install.
onThisDay 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 onThisDay 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 onThisDay. 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.
onThisDay is provided by the Wikipedia MCP Server MCP server (scotthelm/wikipedia-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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