Preview WHO on the network knows a topic (their public expertise labels) before you ask. Read-only; returns matching people's PUBLIC topic labels only.
AI agents call who_knows to retrieve information from Multiplayer MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
topic | string | — | what you're looking for |
Parameters from the server's own tool schema.
This tool retrieves public expertise information from network participants—a straightforward read operation with no capability to modify, execute, or delete data. The read-only designation and public-only scope confirm it poses minimal security risk.
From the tool's definition Tool description explicitly states 'Read-only' and 'returns matching people's PUBLIC topic labels only.' The tool performs a query operation to preview expertise information without any side effects or data modification.
Attacks that exploit this kind of access
Preview WHO on the network knows a topic (their public expertise labels) before you ask. Read-only; returns matching people's PUBLIC topic labels only. It is categorised as a Read tool in the Multiplayer MCP Server MCP Server, which means it retrieves data without modifying state.
who_knows accepts 1 parameter: topic. The full parameter table on this page comes from the server's own tool schema.
Register the Multiplayer MCP Server MCP server in PolicyLayer and add a rule for who_knows: 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 Multiplayer MCP Server. Nothing to install.
who_knows 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 who_knows 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 who_knows. 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.
who_knows is provided by the Multiplayer MCP Server MCP server (https://joinmultiplayer.ai/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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