"What broader phenotype is [HP:N] under" / "parent term of [HPO ID]" — direct parents of an HPO term in the ontology graph. Use to walk up to a more general phenotype class.
Part of the Hpo Api server.
Free to start. No card required.
AI agents call term_parents to retrieve information from Hpo Api 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 term_parents 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": {
"term_parents": {}
}
}See the full Hpo Api policy for all 27 tools.
These attack patterns abuse exactly the kind of access term_parents 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.
"What broader phenotype is [HP:N] under" / "parent term of [HPO ID]" — direct parents of an HPO term in the ontology graph. Use to walk up to a more general phenotype class.. It is categorised as a Read tool in the Hpo Api MCP Server, which means it retrieves data without modifying state.
Register the Hpo Api MCP server in PolicyLayer and add a rule for term_parents: 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 Hpo Api. Nothing to install.
term_parents 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 term_parents 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 term_parents. 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.
term_parents is provided by the Hpo Api MCP server (https://gateway.pipeworx.io/hpo-api/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 27 Hpo Api tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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