Search the npctypes.txt file for NPC (non-player character) definitions.
AI agents call search_npctypes to retrieve information from OSRS MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves NPC definitions from a static or read-only data file. It has no capability to modify game state, execute commands, delete data, or commit financial transactions. The search operation is a standard read query against game metadata. Severity is low because misuse would at worst return irrelevant NPC data to an AI agent, with no harmful consequences to the game or user.
From the tool's definition Tool searches a data file ('npctypes.txt') for NPC definitions. The verb 'search' and the action of querying game data definitions indicate retrieval without modification or side effects.
Documented attack patterns abuse exactly the kind of access search_npctypes gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and OSRS MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for search_npctypes:
{
"version": "1",
"default": "deny",
"tools": {
"search_npctypes": {}
}
}search_npctypes is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Search the npctypes.txt file for NPC (non-player character) definitions. It is categorised as a Read tool in the OSRS MCP Server MCP Server, which means it retrieves data without modifying state.
Register the OSRS MCP Server MCP server in PolicyLayer and add a rule for search_npctypes: 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 OSRS MCP Server. Nothing to install.
search_npctypes 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 search_npctypes 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 search_npctypes. 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.
search_npctypes is provided by the OSRS MCP Server MCP server (jayarrowz/mcp-osrs). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from OSRS MCP Server, 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.
23 OSRS MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.