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

# Tool Error Middleware

> Middleware for handling tool validation and execution errors API Documentation

export const RandomGradientBackground = ({className, color, children, grayscaled = false}) => {
  const saturation = useMemo(() => {
    if (color) {
      const values = color.split("(")[1].split(")")[0].trim().split(/\s+/);
      return parseFloat(values[1] || "0");
    }
    return grayscaled ? 0 : 0.2;
  }, [color, grayscaled]);
  const lightness = useMemo(() => {
    if (color) {
      const values = color.split("(")[1].split(")")[0].trim().split(/\s+/);
      return parseFloat(values[0] || "0.5");
    }
    return grayscaled ? 0.3 : 0.4;
  }, [color, grayscaled]);
  const randomHue = useMemo(() => {
    if (color) {
      const values = color.split("(")[1].split(")")[0].trim().split(/\s+/);
      return parseFloat(values[2] || "0");
    }
    return Math.floor(Math.random() * 360);
  }, [color]);
  const randomColor = useMemo(() => {
    if (color) {
      return color;
    }
    return `oklch(${Math.min(lightness, 1)} ${saturation} ${randomHue})`;
  }, [randomHue, saturation, lightness]);
  const lightColor = useMemo(() => {
    return `oklch(${Math.min(lightness * 2, 1)} ${saturation} ${randomHue})`;
  }, [randomHue, saturation, lightness, color]);
  const direction = useMemo(() => {
    return Math.floor(Math.random() * 360);
  }, [randomHue]);
  const brightnessFilter = useMemo(() => {
    return "1000%";
  }, []);
  return <div className={`relative overflow-hidden ${className || ""}`} style={{
    background: `${lightColor}`,
    minHeight: '100%',
    width: '100%'
  }}>
      <div className="absolute inset-0 w-full h-full" style={{
    background: `linear-gradient(${direction}deg, ${randomColor}, transparent), url(https://grainy-gradients.vercel.app/noise.svg)`,
    filter: `contrast(120%) brightness(${brightnessFilter})`,
    backgroundSize: 'cover',
    backgroundRepeat: 'no-repeat'
  }} />
      {children && <div className="relative z-10 w-full h-full">{children}</div>}
    </div>;
};

<Callout type="info" title="Source Code">
  View the source code for this module on GitHub: <a href="https://github.com/mcp-use/mcp-use/blob/main/libraries/python/mcp_use/agents/middleware/tool_error_middleware.py" target="_blank" rel="noopener noreferrer">[https://github.com/mcp-use/mcp-use/blob/main/libraries/python/mcp\_use/agents/middleware/tool\_error\_middleware.py](https://github.com/mcp-use/mcp-use/blob/main/libraries/python/mcp_use/agents/middleware/tool_error_middleware.py)</a>
</Callout>

Middleware for handling tool validation and execution errors.

This middleware wraps tool calls to catch any exceptions (including ValidationErrors)
and returns them as formatted error messages to the LLM, enabling automatic retry.