Lists all legal moves for the current player in UCI notation.
AI agents call get_valid_moves to retrieve information from MCP Chess Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves information about valid moves without making changes to the board state or game. It is a pure read operation that provides data to inform decision-making, similar to querying the current game state. There are no side effects, no code execution beyond computing legal move generation, and no destructive or financial implications.
From the tool's definition The tool 'get_valid_moves' lists all legal moves for the current player in UCI notation. The description uses 'lists' and 'legal moves', which are query/retrieval operations with no modification of game state.
Documented attack patterns abuse exactly the kind of access get_valid_moves gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Chess Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_valid_moves:
{
"version": "1",
"default": "deny",
"tools": {
"get_valid_moves": {}
}
}get_valid_moves is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Lists all legal moves for the current player in UCI notation. It is categorised as a Read tool in the MCP Chess Server MCP Server, which means it retrieves data without modifying state.
Register the MCP Chess Server MCP server in PolicyLayer and add a rule for get_valid_moves: 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 MCP Chess Server. Nothing to install.
get_valid_moves 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 get_valid_moves 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 get_valid_moves. 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.
get_valid_moves is provided by the MCP Chess Server MCP server (jiayao/mcp-chess). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCP Chess 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.
6 MCP Chess Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.