wavetermdev/waveterm · error

missing values parameter

Error message

missing values parameter

What it means

The tool callback successfully coerced input to a map but the required key "values" is absent. The tool's JSON schema declares "values" as required, so a call omitting it violates the contract and this error is returned to the model so it can retry with correct arguments.

Source

Thrown at pkg/aiusechat/tools.go:294

					"type": "array",
					"items": map[string]any{
						"type": "integer",
					},
					"description": "Array of numbers to add together",
				},
			},
			"required":             []string{"values"},
			"additionalProperties": false,
		},
		ToolAnyCallback: func(input any, toolUseData *uctypes.UIMessageDataToolUse) (any, error) {
			inputMap, ok := input.(map[string]any)
			if !ok {
				return nil, fmt.Errorf("invalid input format")
			}

			valuesInterface, ok := inputMap["values"]
			if !ok {
				return nil, fmt.Errorf("missing values parameter")
			}

			valuesSlice, ok := valuesInterface.([]any)
			if !ok {
				return nil, fmt.Errorf("values must be an array")
			}

			if len(valuesSlice) == 0 {
				return 0, nil
			}

			sum := 0
			for i, val := range valuesSlice {
				floatVal, ok := val.(float64)
				if !ok {
					return nil, fmt.Errorf("value at index %d is not a number", i)
				}
				sum += int(floatVal)

View on GitHub (pinned to a4447c1563)

Solutions

1. Include the required "values" key in the tool arguments: {"values": [1,2,3]}
2. Improve the tool description/prompt so the model uses the exact parameter name "values"
3. If the schema is rendered for the model, confirm the required:["values"] constraint is being advertised to the client

Example fix

// before
anySum({})
// after
anySum({"values": [1, 2, 3]})

m, ok := raw.(map[string]any); if !ok { return errors.New("input not an object") }; if _, ok := m["values"]; !ok { return errors.New("values is required") }

func hasValues(m map[string]any) bool { _, ok := m["values"]; return ok }

out, err := tool.Call(input); if err != nil && strings.Contains(err.Error(), "missing values") { retryWithCorrection(err.Error()) }

When it happens

Trigger: LLM invokes the any-sum tool with an object that lacks the "values" key, e.g. {} or {"numbers": [1,2]} — schema-required parameter missing from the arguments map.

Common situations: Model hallucinating alternate parameter names (numbers, list, items); truncation of generated arguments; hand-written tool call payloads missing the key; prompt instructions that don't name the parameter explicitly.

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

• invalid input format
• missing contents parameter
• missing edits parameter
• values must be an array
• value at index %d is not a number

AI-assisted analysis of wavetermdev/waveterm@a4447c1563 (2026-09-01). Data as JSON: /api/errors/2c33a44c6aa238be. Report an issue: GitHub.