User \u00b7 query user. Variables: after, filter, first, order, after1, filter1, first1, order1, after2, filter2, first2, order2, id. Example variables: {\
AI agents call user to retrieve information from ReliaQuest GreyMatter MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool retrieves user information via GraphQL query parameters. It does not create, modify, delete, or execute operations—it only reads data. Severity is medium because user data is often sensitive (names, IDs, organizational details), and an AI agent could extract information from multiple users through filters and pagination, but cannot modify or delete it.
From the tool's definition Tool name is 'user' and description states 'query user' with query parameters (after, filter, first, order, id). This is a data retrieval/query operation with no side effects.
Attacks that exploit this kind of access
User \u00b7 query user. Variables: after, filter, first, order, after1, filter1, first1, order1, after2, filter2, first2, order2, id. Example variables: {\. It is categorised as a Read tool in the ReliaQuest GreyMatter MCP Server MCP Server, which means it retrieves data without modifying state.
Register the ReliaQuest GreyMatter MCP Server MCP server in PolicyLayer and add a rule for user: 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 ReliaQuest GreyMatter MCP Server. Nothing to install.
user 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 user 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 user. 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.
user is provided by the ReliaQuest GreyMatter MCP Server MCP server (space-c0wboy/reliaquest-greymatter-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.
Teams ship this data inside their own products. See what a licence covers →