tengu_v3_reference_lookup
REVERSE IDENTIFIER LOOKUP — give it a CUSIP, ISIN, SEDOL, ticker, estimate-vendor ticker, gvkey, regulator filer number, entity id or private-company-graph id and it returns the security (or, for an ISSUER key, every security under that issuer) plus which rung matched and whether that binding is ...
This record as markdown: /tools/tengu-mcp/tengu-v3-reference-lookup.md
What tengu_v3_reference_lookup does on Tengu
AI agents call tengu_v3_reference_lookup to retrieve information from Tengu without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
cik | string | — | |
isin | string | — | |
cusip | string | — | |
gvkey | string | — | |
ibtic | string | — | |
sedol | string | — | |
ticker | string | — | |
entity_id | string | — | |
include_retired | boolean | — | |
private_company_id | string | — |
Parameters from the server's own tool schema.
Why tengu_v3_reference_lookup is rated Low
Even though tengu_v3_reference_lookup only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Risk signalsHigh parameter count (10 properties) · Bulk/mass operation — affects multiple targets
Attacks that exploit this kind of access
The rule that runs tengu_v3_reference_lookup safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Tengu, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For tengu_v3_reference_lookup, this is the rule to start with:
tengu_v3_reference_lookup 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 Tengu, apply this rule, and every tengu_v3_reference_lookup call is checked against it from then on.
Questions about tengu_v3_reference_lookup
REVERSE IDENTIFIER LOOKUP — give it a CUSIP, ISIN, SEDOL, ticker, estimate-vendor ticker, gvkey, regulator filer number, entity id or private-company-graph id and it returns the security (or, for an ISSUER key, every security under that issuer) plus which rung matched and whether that binding is still current. Exactly one identifier per call. RETIRED identifiers resolve by default — 759,618 of the 969,333 bindings on file are retired, which is precisely why a stale identifier in your own data still lands, and it comes back with the date it was replaced and by what. Issuer keys NEVER nominate one security: an issuer can carry a common line, other share classes and a foreign listing, so all of them are returned and the grain is stated. Use it to turn a CUSIP-keyed custodian file into tickers, to find the ticker behind a regulator filing, or to audit whether an identifier in your own data has gone stale. Rung coverage, measured 2026-08-02: CUSIP9 and CUSIP8 100% of 77,313 securities, ISIN 79.4%, SEDOL 74.2%, regulator filer number 67.8%, estimate-vendor ticker 37.2%. It is categorised as a Read tool in the Tengu MCP Server, which means it retrieves data without modifying state.
tengu_v3_reference_lookup accepts 10 parameters: cik, isin, cusip, gvkey, ibtic, sedol, ticker, entity_id, include_retired, private_company_id. The full parameter table on this page comes from the server's own tool schema.
Register the Tengu MCP server in PolicyLayer and add a rule for tengu_v3_reference_lookup: 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 Tengu. Nothing to install.
tengu_v3_reference_lookup 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 tengu_v3_reference_lookup 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 tengu_v3_reference_lookup. 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.
tengu_v3_reference_lookup is provided by the Tengu MCP server (Hlobo-dev/tengu-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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