> ## Documentation Index
> Fetch the complete documentation index at: https://agent-observability-docs.splunk.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Expression and Readability Evaluators

> Assess the style, tone, and clarity of your AI's generated content using Splunk Agent Observability's expression and readability evaluators

export const ModalityIcons = ({modalities}) => {
  const iconProps = {
    fill: "none",
    height: 20,
    width: 20,
    stroke: "currentColor",
    strokeLinecap: "round",
    strokeLinejoin: "round",
    strokeWidth: 2,
    viewBox: "0 0 24 24",
    xmlns: "http://www.w3.org/2000/svg"
  };
  const renderIcon = modality => {
    if (modality === "Text") {
      return <svg {...iconProps} aria-hidden="true">
          <circle cx="12" cy="12" r="9" />
          <path d="M8 8h8M12 8v8" />
        </svg>;
    }
    if (modality === "Image/PDF") {
      return <svg {...iconProps} aria-hidden="true">
          <rect height="18" rx="2" width="18" x="3" y="3" />
          <circle cx="8.5" cy="8.5" r="1.5" />
          <path d="m21 15-5-5L5 21" />
        </svg>;
    }
    if (modality === "Audio") {
      return <svg {...iconProps} aria-hidden="true">
          <path d="M9 18V5l10-2v13" />
          <circle cx="6" cy="18" r="3" />
          <circle cx="16" cy="16" r="3" />
        </svg>;
    }
    return null;
  };
  return <span aria-label={`Supported modalities: ${modalities.join(", ")}`} role="group" style={{
    display: "inline-flex",
    alignItems: "center",
    gap: "0.5rem"
  }}>
      {modalities.map(modality => <span aria-label={modality} key={modality} role="img" style={{
    display: "inline-flex",
    flexShrink: 0
  }} title={modality}>
          {renderIcon(modality)}
        </span>)}
    </span>;
};

Expression and readability evaluators help you evaluate how well your AI communicates—not just what it says, but how it says it. These evaluators are important when you want your AI to produce content that is clear, on-brand, and easy for users to understand.

Use these evaluators when you want to:

* Ensure your AI's responses match your brand's voice and tone.
* Check that generated content is clear, concise, and appropriate for your audience.
* Quantitatively measure the quality of generated text compared to human-written references.

Below is a quick reference table of all expression and readability evaluators:

| Name                                                         | Description                                             | Supported Nodes                | Modalities                              | When to Use                                                                       | Example Use Case                                                                                                                 |
| :----------------------------------------------------------- | :------------------------------------------------------ | :----------------------------- | :-------------------------------------- | :-------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------- |
| [Tone](/concepts/evaluators/expression-and-readability/tone) | Evaluates the emotional tone and style of the response. | Trace (root input/output only) | <ModalityIcons modalities={["Text"]} /> | When the style and tone of AI responses matter for your brand or user experience. | A luxury brand's customer service chatbot that must maintain a sophisticated, professional tone consistent with the brand image. |

***

## Next steps

* [Back to Evaluators Overview](/concepts/evaluators/overview)
* [Compare all evaluators](/concepts/evaluators/evaluator-comparison)