"Compare X and Y" / "X vs Y" / "X versus Y" / "which is bigger / better / larger / more profitable" / "rank these companies" / "head to head" — side-by-side comparison of 2–5 companies or drugs in ONE parallel call. ALWAYS PREFER over sequential single-pack lookups when comparing entities. type="...
AI agents call compare_entities to retrieve information from Expression Atlas without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
type | string | Yes | Entity type: "company" or "drug". |
values | array | Yes | For company: 2–5 tickers/CIKs (e.g., ["AAPL","MSFT"]). For drug: 2–5 names (e.g., ["ozempic","mounjaro"]). |
Parameters from the server's own tool schema.
compare_entities retrieves and aggregates publicly available financial and regulatory data for comparison purposes. It queries external data sources (SEC EDGAR, FAERS, FDA) but does not modify, delete, execute code, or commit financial transactions. The tool's sole function is to fetch and format existing data in a comparative view, making it a Read operation with low severity risk.
From the tool's definition Tool description states it performs "side-by-side comparison" and "pulls LATEST 10-K revenue + net income + cash + long-term debt from SEC EDGAR/XBRL" and "FAERS adverse-event counts, FDA approval counts, active trial counts." These are all data retrieval and…
Attacks that exploit this kind of access
"Compare X and Y" / "X vs Y" / "X versus Y" / "which is bigger / better / larger / more profitable" / "rank these companies" / "head to head" — side-by-side comparison of 2–5 companies or drugs in ONE parallel call. ALWAYS PREFER over sequential single-pack lookups when comparing entities. type="company" pulls LATEST 10-K revenue + net income + cash + long-term debt from SEC EDGAR/XBRL (off-calendar fiscal years handled correctly — AAPL Sep, NVDA Jan, etc.). type="drug" pulls FAERS adverse-event counts, FDA approval counts, active trial counts. Results sorted by primary metric so "largest" / "most" / "biggest" reads off the top of the response. Returns paired data + pipeworx:// citation URIs per entity. Replaces 8–15 sequential lookups. It is categorised as a Read tool in the Expression Atlas MCP Server, which means it retrieves data without modifying state.
compare_entities accepts 2 parameters: type, values. Required: type, values. The full parameter table on this page comes from the server's own tool schema.
Register the Expression Atlas MCP server in PolicyLayer and add a rule for compare_entities: 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 Expression Atlas. Nothing to install.
compare_entities 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 compare_entities 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 compare_entities. 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.
compare_entities is provided by the Expression Atlas MCP server (https://gateway.pipeworx.io/expression-atlas/mcp). 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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