Find UIDs linked between Entrez databases (e.g., SNP records linked to Nucleotide, Domain records linked to Protein). Essential for discovering related data across NCBI
AI agents call elink to retrieve information from Entrez MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a data retrieval operation that discovers associations between existing records in different Entrez databases. It has no side effects, does not modify data, execute code, delete records, or commit financial obligations. The blast radius of misuse is minimal—an agent could retrieve unwanted linked UIDs but cannot damage data or trigger external operations.
From the tool's definition elink: 'Find UIDs linked between Entrez databases' — retrieves relationship data between records without modifying, deleting, or executing code. The tool queries and returns linked identifiers across NCBI databases.
Attacks that exploit this kind of access
Find UIDs linked between Entrez databases (e.g., SNP records linked to Nucleotide, Domain records linked to Protein). Essential for discovering related data across NCBI. It is categorised as a Read tool in the Entrez MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Entrez MCP Server MCP server in PolicyLayer and add a rule for elink: 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 Entrez MCP Server. Nothing to install.
elink 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 elink 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 elink. 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.
elink is provided by the Entrez MCP Server MCP server (leongxj123/entrez-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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