Get lead field metadata and schema information from Marketo.
AI agents call describe_leads to retrieve information from Marketo MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The describe_leads tool queries and returns schema metadata about leads in Marketo. This is a read-only operation that retrieves information without creating, modifying, deleting, or executing any changes. The blast radius of misuse is minimal since it only exposes structural data definitions rather than actual lead records or sensitive operational data. Low severity is appropriate for metadata retrieval operations.
From the tool's definition Tool retrieves 'lead field metadata and schema information' from Marketo—a data retrieval operation with no modification capability.
Attacks that exploit this kind of access
Get lead field metadata and schema information from Marketo. It is categorised as a Read tool in the Marketo MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Marketo MCP Server MCP server in PolicyLayer and add a rule for describe_leads: 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 Marketo MCP Server. Nothing to install.
describe_leads 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 describe_leads 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 describe_leads. 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.
describe_leads is provided by the Marketo MCP Server MCP server (tyron-pretorius/marketo-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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