AI agents call eval_hallucination to retrieve information from Multivon without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Based on the tool name and server context (evaluation tools for AI coding agents), this tool likely evaluates or scores hallucination in AI-generated outputs, which is a read/analysis operation. Sibling tools like eval_faithfulness, eval_bias, and eval_answer_accuracy all suggest read-only evaluation tasks. However, the empty description lowers confidence significantly.
From the tool's definition Tool name is 'eval_hallucination'; description is empty and uninformative.
Attacks that exploit this kind of access
eval_hallucination. It is categorised as a Read tool in the Multivon MCP Server, which means it retrieves data without modifying state.
Register the Multivon MCP server in PolicyLayer and add a rule for eval_hallucination: 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 Multivon. Nothing to install.
eval_hallucination 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 eval_hallucination 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 eval_hallucination. 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.
eval_hallucination is provided by the Multivon MCP server (multivon-ai/multivon-mcp). 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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