JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tbody>
        <tr>
            <td>Video Title:</td>
            <td>
                <input type="text" name="param[30301754][title]" value="VIDEO TITLE" autocomplete="on" />
            </td>
        </tr>
        <tr>
            <td>File name:</td>
            <td>
                <input type="text" name="param[30301754][filename]" value="FILE NAME" autocomplete="on" />.3gp</td>
        </tr>
        <tr>
            <td>Description:</td>
            <td>
                <textarea name="param[30301754][description]"></textarea>
            </td>
        </tr>
    </tbody>
</table>

JavaScript

javascript: (function () {
    if (!($ = window.jQuery)) {
        script = document.createElement('script');
        script.src = 'http://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js';
        script.onload = doAutoFill;
        document.body.appendChild(script);
    } else {
        doAutoFill();
    }

    function doAutoFill() {
        var textToFill = prompt("Enter text to fill:");
        if (textToFill != null) $("textarea[name$=\\[description\\]]").val(textToFill);
    }
})();