[CUSTOM] Calls the Marketo REST API directly (not Adobe's native MCP).
AI agents call custom_describe_opportunities 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 tool name contains 'describe', which conventionally means fetching schema or metadata about an object (e.g., Salesforce-style describe calls). This maps to a Read operation. However, the description is uninformative — it only states it calls the Marketo REST API directly without specifying the endpoint, HTTP method, or whether it has side effects.
From the tool's definition 'custom_describe_opportunities' and '[CUSTOM] Calls the Marketo REST API directly' — 'describe' strongly implies a metadata/schema retrieval operation (Read), but the vague description 'Calls the Marketo REST API directly' leaves the actual HTTP method and…
Attacks that exploit this kind of access
[CUSTOM] Calls the Marketo REST API directly (not Adobe's native MCP). 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 custom_describe_opportunities: 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.
custom_describe_opportunities 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 custom_describe_opportunities 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 custom_describe_opportunities. 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.
custom_describe_opportunities 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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