{"record":{"id":"95910585433ec5ca","repo":"vercel/ai","slug":"invalidparams","errorCode":"InvalidParams","errorMessage":"Unknown host tool: ${request.params.name}","messagePattern":"Unknown host tool: (.+?)","errorType":"error_code","errorClass":"McpError","httpStatus":null,"severity":"error","filePath":"packages/harness-acp/src/v1/bridge/host-tool-mcp-server.ts","lineNumber":76,"sourceCode":"  server.setRequestHandler(ListToolsRequestSchema, async () => {\n    if (catalogAcknowledgmentError != null) {\n      throw catalogAcknowledgmentError;\n    }\n    const current = catalog;\n    if (onListTools != null) {\n      setImmediate(() => {\n        void onListTools({ revision: current.revision }).catch(error => {\n          catalogAcknowledgmentError = error;\n        });\n      });\n    }\n    return { tools: current.tools.map(toMCPTool) };\n  });\n  server.setRequestHandler(CallToolRequestSchema, async request => {\n    const current = catalog;\n    const tool = current.byName.get(request.params.name);\n    if (tool == null) {\n      throw new McpError(\n        ErrorCode.InvalidParams,\n        `Unknown host tool: ${request.params.name}`,\n      );\n    }\n    const input = request.params.arguments ?? {};\n    const result = await invoke({\n      toolName: tool.name,\n      input,\n      catalogRevision: current.revision,\n    });\n    return toCallToolResult({ result });\n  });\n\n  return {\n    server,\n    updateCatalog: async ({ revision: nextRevision, tools: nextTools }) => {\n      catalog = createCatalog({\n        revision: nextRevision,","sourceCodeStart":58,"sourceCodeEnd":94,"githubUrl":"https://github.com/vercel/ai/blob/69428b1f8b037e4d118fb4853428d5c4e620493c/packages/harness-acp/src/v1/bridge/host-tool-mcp-server.ts#L58-L94","documentation":"Error \"Unknown host tool: ${request.params.name}\" thrown in vercel/ai.","triggerScenarios":"Thrown at packages/harness-acp/src/v1/bridge/host-tool-mcp-server.ts:76 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"69428b1f8b037e4d118fb4853428d5c4e620493c","analyzedAt":"2026-08-30T12:32:21.016Z","schemaVersion":2},"datasetVersion":"2026-08-30T13:17:10.514Z"}