mcp-tool-schema-definiti-tool-call-returns-mcperror-with-keyvalidator-parse-952b0bd3

THEN Pass the input schema as a plain object (`{ paramName: z.string() }`) instead of a `z.object()` instance. The MCP SDK expects a raw object mapping each parameter to a Zod type, not a ZodObject. Also ensure you are using Zod v3.x, or adjust for v4 compatibility by following this pattern.

// ❌ INCORRECT: wrapping in z.object() causes error
server.tool("my_tool", z.object({ query: z.string() }), handler);

// ✅ CORRECT: pass plain object
server.tool("my_tool", { query: z.string() }, handler);