Check if cached entity content is still current. Pass a previously received version_hash to verify freshness. Returns current version info.
AI agents call check_version to retrieve information from Hippocampus without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a read-only verification operation. It takes a version_hash parameter and returns current version information to determine if cached data is stale. There are no side effects, no data creation/modification, no code execution, and no destructive operations. It is a simple integrity/freshness check mechanism typical of cache management systems.
From the tool's definition Tool 'check_version' described as checking and verifying if cached entity content is current by passing a version_hash and returning version info—a pure query operation with no data modification or external execution.
Documented attack patterns abuse exactly the kind of access check_version gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Hippocampus, and nothing reaches the server without passing your rules. This is the rule we recommend for check_version:
{
"version": "1",
"default": "deny",
"tools": {
"check_version": {}
}
}check_version is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Check if cached entity content is still current. Pass a previously received version_hash to verify freshness. Returns current version info. It is categorised as a Read tool in the Hippocampus MCP Server, which means it retrieves data without modifying state.
Register the Hippocampus MCP server in PolicyLayer and add a rule for check_version: 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 Hippocampus. Nothing to install.
check_version 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_version 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_version. 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_version is provided by the Hippocampus MCP server (karrolcia/hippocampus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Hippocampus, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
11 Hippocampus tools catalogued and risk-classified — across an index of 43,000+ MCP servers.