AI agents call health_check to retrieve information from Mcp Base without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a read-only health check operation that queries the server's status without modifying, executing external operations, or causing side effects. No data is created, modified, or deleted. The only output is informational.
From the tool's definition Tool returns health status with no side effects: 'Return a simple health status indicating the server is running'
Attacks that exploit this kind of access
Return a simple health status indicating the server is running. It is categorised as a Read tool in the Mcp Base MCP Server, which means it retrieves data without modifying state.
Register the Mcp Base MCP server in PolicyLayer and add a rule for health_check: 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 Mcp Base. Nothing to install.
health_check 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 health_check 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 health_check. 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.
health_check is provided by the Mcp Base MCP server (sesopenko/mcp-filesystem-readonly). 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.
Teams ship this data inside their own products. See what a licence covers →