Validate an ISIN (ISO 6166 securities identifier): 2-letter country + 9-char NSIN + Luhn check digit. Returns valid, country, nsin, and the embedded CUSIP for US/CA issues. Catches transposed chars in security master data.
AI agents call validate.isin to retrieve information from Mcp without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs format validation and parsing of a securities identifier string. It retrieves and returns structural information (country code, NSIN, CUSIP) without creating, modifying, executing, deleting, or moving money.
From the tool's definition Tool description states it 'Validate[s] an ISIN' and 'Returns valid, country, nsin, and the embedded CUSIP'. The verb is validation/checking, not modification, execution, or deletion. The output is informational (boolean validity, parsed fields).
Attacks that exploit this kind of access
Validate an ISIN (ISO 6166 securities identifier): 2-letter country + 9-char NSIN + Luhn check digit. Returns valid, country, nsin, and the embedded CUSIP for US/CA issues. Catches transposed chars in security master data. It is categorised as a Read tool in the Mcp MCP Server, which means it retrieves data without modifying state.
Register the MCP server in PolicyLayer and add a rule for validate.isin: 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 Mcp. Nothing to install.
validate.isin 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 validate.isin 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 validate.isin. 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.
validate.isin is provided by the MCP server (@2sio/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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