Mark a session as completed and refresh its summary.
AI agents call end_session to retrieve information from Agent Evidence MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Even though end_session only reads data, uncontrolled read access leaks sensitive information and racks up API costs — an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
Mark a session as completed and refresh its summary. It is categorised as a Read tool in the Agent Evidence MCP MCP Server, which means it retrieves data without modifying state.
Register the Agent Evidence MCP server in PolicyLayer and add a rule for end_session: 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 Agent Evidence MCP. Nothing to install.
end_session 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 end_session 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 end_session. 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.
end_session is provided by the Agent Evidence MCP server (xiexie-qiuligao/agent-evidence-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.