Extract an N-hop neighborhood subgraph around a document. Returns deduplicated nodes and edges with distance from root.
AI agents call knowledge_subgraph to retrieve information from Ralph Hero without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves graph data (nodes and edges) from what appears to be a knowledge graph or document relationship system. It performs a read-only neighborhood traversal operation centered on a document, returning structured information without creating, modifying, or deleting any data. This is a classic Read operation with minimal risk profile.
From the tool's definition Tool description states 'Extract an N-hop neighborhood subgraph around a document' and 'Returns deduplicated nodes and edges with distance from root.' The verb 'Extract' and 'Returns' indicate data retrieval with no modifications.
Risk signalsAdmin/system-level operation
Attacks that exploit this kind of access
Extract an N-hop neighborhood subgraph around a document. Returns deduplicated nodes and edges with distance from root. It is categorised as a Read tool in the Ralph Hero MCP Server, which means it retrieves data without modifying state.
Register the Ralph Hero MCP server in PolicyLayer and add a rule for knowledge_subgraph: 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 Ralph Hero. Nothing to install.
knowledge_subgraph 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 knowledge_subgraph 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 knowledge_subgraph. 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.
knowledge_subgraph is provided by the Ralph Hero MCP server (ralph-hero-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.
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