Check if a character knows a specific secret
AI agents call check_knows_secret to retrieve information from DMCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves or queries whether a character possesses knowledge of a secret within the RPG game state. It performs no side effects, creates no data, executes no external code, and causes no irreversible changes. It is a straightforward read operation within the game's data structure, consistent with a dungeon master checking campaign knowledge.
From the tool's definition Tool name 'check_knows_secret' and description 'Check if a character knows a specific secret' indicate a query operation that retrieves game state information without modification.
Documented attack patterns abuse exactly the kind of access check_knows_secret gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and DMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for check_knows_secret:
{
"version": "1",
"default": "deny",
"tools": {
"check_knows_secret": {}
}
}check_knows_secret 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 a character knows a specific secret. It is categorised as a Read tool in the DMCP MCP Server, which means it retrieves data without modifying state.
Register the D MCP server in PolicyLayer and add a rule for check_knows_secret: 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 DMCP. Nothing to install.
check_knows_secret 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_knows_secret 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_knows_secret. 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_knows_secret is provided by the D MCP server (shawnrushefsky/dmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from DMCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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204 DMCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.