Search across all 38+ Entrez databases simultaneously to see hit counts for your query in each database. Global version of ESearch that helps identify which databases contain relevant data before focused searches.
AI agents call egquery 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.
egquery performs a read-only search across NCBI databases to return aggregate hit counts for a query term. This is a passive information retrieval operation with no side effects, no code execution, no data modification, and no data destruction. The tool simply counts matches across databases to help users identify relevant resources.
From the tool's definition The tool 'Search across all 38+ Entrez databases simultaneously to see hit counts' and 'helps identify which databases contain relevant data' describes a query operation that retrieves hit counts without modifying, executing, or destructing any data.
Attacks that exploit this kind of access
Search across all 38+ Entrez databases simultaneously to see hit counts for your query in each database. Global version of ESearch that helps identify which databases contain relevant data before focused searches. 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 egquery: 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.
egquery 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 egquery 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 egquery. 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.
egquery 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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