{"record":{"id":"05175f21f43caaed","repo":"googleapis/mcp-toolbox","slug":"description-is-required-for-tool-q-05175f","errorCode":null,"errorMessage":"description is required for tool %q","messagePattern":"description is required for tool %q","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"internal/tools/clickhouse/clickhouselistdatabases/clickhouselistdatabases.go","lineNumber":65,"sourceCode":"}\n\ntype Config struct {\n\ttools.ConfigBase `yaml:\",inline\"`\n\tType             string                 `yaml:\"type\" validate:\"required\"`\n\tSource           string                 `yaml:\"source\" validate:\"required\"`\n\tParameters       parameters.Parameters  `yaml:\"parameters\"`\n\tAnnotations      *tools.ToolAnnotations `yaml:\"annotations,omitempty\"`\n}\n\nvar _ tools.ToolConfig = Config{}\n\nfunc (cfg Config) ToolConfigType() string {\n\treturn listDatabasesType\n}\n\nfunc (cfg Config) Initialize(context.Context) (tools.Tool, error) {\n\tif cfg.Description == \"\" {\n\t\treturn nil, fmt.Errorf(\"description is required for tool %q\", cfg.Name)\n\t}\n\n\tallParameters, paramManifest, err := parameters.ProcessParameters(nil, cfg.Parameters)\n\tif err != nil {\n\t\treturn nil, err\n\t}\n\n\treturn Tool{\n\t\tBaseTool: tools.NewBaseTool(\n\t\t\tcfg,\n\t\t\ttools.GetAnnotationsOrDefault(cfg.Annotations, tools.NewReadOnlyAnnotations),\n\t\t\ttools.Manifest{Description: cfg.Description, Parameters: paramManifest, AuthRequired: cfg.AuthRequired},\n\t\t\tallParameters,\n\t\t),\n\t}, nil\n}\n\nvar _ tools.Tool = Tool{}","sourceCodeStart":47,"sourceCodeEnd":83,"githubUrl":"https://github.com/googleapis/mcp-toolbox/blob/8cc6e09de2ad7b8bffc77751799585a1401a48eb/internal/tools/clickhouse/clickhouselistdatabases/clickhouselistdatabases.go#L47-L83","documentation":"Config.Initialize for clickhouse-list-databases validates that every tool needs a non-empty `description`, since descriptions are exposed to LLM clients in the tool manifest. An empty description makes the tool useless to model clients, so initialization fails fast.","triggerScenarios":"Loading a YAML tools file where a `clickhouse-list-databases` tool entry omits the `description` field or sets it to \"\"; constructing Config{Name: \"x\"} in Go and calling Initialize directly (as the unit tests do).","commonSituations":"Hand-written minimal tool configs; generated configs with dropped fields; YAML key typo like `descriptions:` so Description unmarshals empty.","solutions":["Add a non-empty `description` field to the tool's YAML block.","Fix key typos so the value actually lands in Config.Description.","If building Config in code, set Description before calling Initialize."],"exampleFix":"// before\nsource: my-clickhouse\nname: list_databases\n// after\nsource: my-clickhouse\nname: list_databases\ndescription: List all databases in the ClickHouse instance.","handlingStrategy":"validation","validationCode":"// Go\ncfg := Config{Name: \"list_databases\", /* ... */}\nif cfg.Description == \"\" {\n    return errors.New(\"clickhouse-list-databases requires a non-empty description\")\n}\nif _, err := cfg.Initialize(context.Background()); err != nil {\n    return err\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Treat `description` as mandatory in every tool block.","Lint YAML configs for required keys (yamllint custom schema).","Keep descriptions user/LLM-oriented and specific to the database."],"tags":["clickhouse","config-validation","missing-field","tool-config"],"backgroundTag":"missing-required-argument","analyzedSha":"8cc6e09de2ad7b8bffc77751799585a1401a48eb","analyzedAt":"2026-09-05T01:10:36.887Z","contentChangedAt":"2026-09-05T01:10:36.887Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}