List all active stateful push subscriptions on this MCP server instance. Returns metadata for each subscription (not the buffered IOCs themselves). Useful for inspecting what agents are currently subscribed and what filters they have configured.
Part of the Nullcone Threat Intelligence server.
Free to start. No card required.
AI agents call list_subscriptions to retrieve information from Nullcone Threat Intelligence without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though list_subscriptions only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"list_subscriptions": {}
}
}See the full Nullcone Threat Intelligence policy for all 30 tools.
These attack patterns abuse exactly the kind of access list_subscriptions gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
List all active stateful push subscriptions on this MCP server instance. Returns metadata for each subscription (not the buffered IOCs themselves). Useful for inspecting what agents are currently subscribed and what filters they have configured.. It is categorised as a Read tool in the Nullcone Threat Intelligence MCP Server, which means it retrieves data without modifying state.
Register the Nullcone Threat Intelligence MCP server in PolicyLayer and add a rule for list_subscriptions: 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 Nullcone Threat Intelligence. Nothing to install.
list_subscriptions 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 list_subscriptions 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 list_subscriptions. 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.
list_subscriptions is provided by the Nullcone Threat Intelligence MCP server (https://nullcone.ai/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 30 Nullcone Threat Intelligence tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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