check_liveness
First principles: liveness from signal freshness (stigmergy + probe + outcomes), not Dual calendar alone.
This record as markdown: /tools/dev-dualregistry-registry/check-liveness.md
What check_liveness does on Dual Registry
AI agents call check_liveness to retrieve information from Dual Registry 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 |
|---|---|---|---|
max_hours | number | — | |
listing_id | string | Yes |
Parameters from the server's own tool schema.
Why check_liveness is rated Low
Even though check_liveness 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.
Attacks that exploit this kind of access
The rule that runs check_liveness safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Dual Registry, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For check_liveness, this is the rule to start with:
check_liveness 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 Dual Registry, apply this rule, and every check_liveness call is checked against it from then on.
Questions about check_liveness
First principles: liveness from signal freshness (stigmergy + probe + outcomes), not Dual calendar alone. It is categorised as a Read tool in the Dual Registry MCP Server, which means it retrieves data without modifying state.
check_liveness accepts 2 parameters: max_hours, listing_id. Required: listing_id. The full parameter table on this page comes from the server's own tool schema.
Register the Dual Registry MCP server in PolicyLayer and add a rule for check_liveness: 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 Dual Registry. Nothing to install.
check_liveness 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 check_liveness 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 check_liveness. 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.
check_liveness is provided by the Dual Registry MCP server (https://www.dualregistry.dev/api/protocol). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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