lookup_entity
Look up a single entity by URI (entity://<slug>) or by canonical name. Backed by the federated search action filtered to nb_entities. Returns the top match
This record as markdown: /tools/io-github-homenshum-nodebench/lookup-entity.md
What lookup_entity does on Nodebench
AI agents call lookup_entity to retrieve information from Nodebench without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why lookup_entity is rated Low
This tool queries an entity database and returns matching results. It performs a read-only retrieval operation without creating, modifying, deleting, or executing anything. The ability to search federated data by URI or name is a classic Read operation with minimal risk—an AI agent could retrieve information but cannot change or harm data.
From the tool's definition Tool description states it 'Look[s] up a single entity by URI or by canonical name' and 'Returns the top match'. The verbs 'look up' and 'returns' are retrieval operations with no side effects.
Attacks that exploit this kind of access
The rule that runs lookup_entity safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Nodebench, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For lookup_entity, this is the rule to start with:
lookup_entity is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Nodebench, apply this rule, and every lookup_entity call is checked against it from then on.
Questions about lookup_entity
Look up a single entity by URI (entity://<slug>) or by canonical name. Backed by the federated search action filtered to nb_entities. Returns the top match. It is categorised as a Read tool in the Nodebench MCP Server, which means it retrieves data without modifying state.
Register the Nodebench MCP server in PolicyLayer and add a rule for lookup_entity: 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 Nodebench. Nothing to install.
lookup_entity 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 lookup_entity 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 lookup_entity. 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.
lookup_entity is provided by the Nodebench MCP server (nodebench-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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