hippo_predicate_graph_check
FORGIA #229 — STRIPS predicate-graph DAG validation.
This record as markdown: /tools/verimem/hippo-predicate-graph-check.md
What hippo_predicate_graph_check does on Verimem
AI agents call hippo_predicate_graph_check to retrieve information from Verimem without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why hippo_predicate_graph_check is rated Low
The tool performs validation of a directed acyclic graph (DAG) structure representing STRIPS predicates. This is inherently a read-only, inspective operation: it queries and analyzes the graph but does not create, modify, delete, or execute external operations. The validation logic has no side effects on the underlying data.
From the tool's definition Tool name contains 'check' and description specifies 'DAG validation' — a diagnostic/validation operation that inspects predicate graph structure without modifying it.
Attacks that exploit this kind of access
The rule that runs hippo_predicate_graph_check safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Verimem, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For hippo_predicate_graph_check, this is the rule to start with:
hippo_predicate_graph_check 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 Verimem, apply this rule, and every hippo_predicate_graph_check call is checked against it from then on.
Questions about hippo_predicate_graph_check
FORGIA #229 — STRIPS predicate-graph DAG validation. It is categorised as a Read tool in the Verimem MCP Server, which means it retrieves data without modifying state.
Register the Verimem MCP server in PolicyLayer and add a rule for hippo_predicate_graph_check: 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 Verimem. Nothing to install.
hippo_predicate_graph_check 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 hippo_predicate_graph_check 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 hippo_predicate_graph_check. 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.
hippo_predicate_graph_check is provided by the Verimem MCP server (aureliocpr-ctrl/verimem). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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