googleapis/mcp-toolbox · error

description is required for tool %q

Error message

description is required for tool %q

What it means

cloudhealthcarefhirpatienteverything.Config.Initialize requires a non-empty description; like the other tools in this repo the description is authored by the user in tools.yaml and cannot be defaulted. An empty value stops tool construction.

Source

Thrown at internal/tools/cloudhealthcare/cloudhealthcarefhirpatienteverything/cloudhealthcarefhirpatienteverything.go:75

}

type Config struct {
	tools.ConfigBase `yaml:",inline"`
	Type             string                 `yaml:"type" validate:"required"`
	Source           string                 `yaml:"source" validate:"required"`
	Annotations      *tools.ToolAnnotations `yaml:"annotations,omitempty"`
}

// validate interface
var _ tools.ToolConfig = Config{}

func (cfg Config) ToolConfigType() string {
	return resourceType
}

func (cfg Config) Initialize(context.Context) (tools.Tool, error) {
	if cfg.Description == "" {
		return nil, fmt.Errorf("description is required for tool %q", cfg.Name)
	}

	params := buildParams(false)
	return Tool{
		BaseTool: tools.NewBaseTool(
			cfg,
			tools.GetAnnotationsOrDefault(cfg.Annotations, tools.NewReadOnlyAnnotations),
			tools.Manifest{Description: cfg.Description, Parameters: params.Manifest(), AuthRequired: cfg.AuthRequired},
			params,
		),
	}, nil
}

// validate interface
var _ tools.Tool = Tool{}

type Tool struct {
	tools.BaseTool[Config]

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Add a meaningful non-empty description to the tool's yaml block
2. Verify the key is exactly 'description' and non-empty
3. Check anchors/overrides don't reset it to ""

Example fix

// before
  patient-everything:
    kind: cloud-healthcare-fhir-patient-everything
    source: healthcare-src
// after
  patient-everything:
    kind: cloud-healthcare-fhir-patient-everything
    source: healthcare-src
    description: "Retrieve all FHIR resources for a patient via Patient/$everything"

func checkDescription(cfg map[string]any) error {
	d, _ := cfg["description"].(string)
	if d == "" { return errors.New("description is required") }
	return nil
}

When it happens

Trigger: A cloud-healthcare-fhir-patient-everything tool entry in tools.yaml with no description field or an empty string value.

Common situations: Omitting description in a quickstart-style minimal config; YAML anchors or templating blanking the field; key typo leaving the struct field zero-valued.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• description is required for tool %q
• description is required for tool %q
• description is required for tool %q
• doc %d: unexpected non-string key in input: %v
• doc %d: invalid config format at key %q: %w

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/e5cd8c52ecc1456d. Report an issue: GitHub.