Skip to main content
Glama
lewisvoncken

Playwright MCP

by lewisvoncken

browser_wait_for

Read-only

Wait for specific text to appear or disappear on a web page, or pause execution for a set duration during browser automation.

Instructions

Wait for text to appear or disappear or a specified time to pass

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
timeNoThe time to wait in seconds
textNoThe text to wait for
textGoneNoThe text to wait for to disappear

Implementation Reference

  • The handler function that implements the logic for the 'browser_wait_for' tool. It handles waiting for a specified time, text to appear (visible), or text to disappear (hidden) using Playwright locators on the current tab.
    handle: async (context, params) => {
      if (!params.text && !params.textGone && !params.time)
        throw new Error('Either time, text or textGone must be provided');
    
      const code: string[] = [];
    
      if (params.time) {
        code.push(`await new Promise(f => setTimeout(f, ${params.time!} * 1000));`);
        await new Promise(f => setTimeout(f, Math.min(10000, params.time! * 1000)));
      }
    
      const tab = context.currentTabOrDie();
      const locator = params.text ? tab.page.getByText(params.text).first() : undefined;
      const goneLocator = params.textGone ? tab.page.getByText(params.textGone).first() : undefined;
    
      if (goneLocator) {
        code.push(`await page.getByText(${JSON.stringify(params.textGone)}).first().waitFor({ state: 'hidden' });`);
        await goneLocator.waitFor({ state: 'hidden' });
      }
    
      if (locator) {
        code.push(`await page.getByText(${JSON.stringify(params.text)}).first().waitFor({ state: 'visible' });`);
        await locator.waitFor({ state: 'visible' });
      }
    
      return {
        code,
        captureSnapshot,
        waitForNetwork: false,
      };
    },
  • The schema definition for the 'browser_wait_for' tool, including name, title, description, and Zod input schema for parameters: time, text, textGone.
    schema: {
      name: 'browser_wait_for',
      title: 'Wait for',
      description: 'Wait for text to appear or disappear or a specified time to pass',
      inputSchema: z.object({
        time: z.number().optional().describe('The time to wait in seconds'),
        text: z.string().optional().describe('The text to wait for'),
        textGone: z.string().optional().describe('The text to wait for to disappear'),
      }),
      type: 'readOnly',
    },
  • The default export that registers the 'browser_wait_for' tool (as 'wait') in an array for inclusion in the MCP tools list.
    export default (captureSnapshot: boolean) => [
      wait(captureSnapshot),
    ];
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations provide readOnlyHint=true, openWorldHint=true, and destructiveHint=false, indicating a safe, non-destructive operation. The description adds behavioral context by specifying what the tool waits for (text appearance/disappearance or time), which isn't covered by annotations. However, it doesn't mention timeout behavior, error handling, or interaction with browser state, leaving some gaps in transparency.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, efficient sentence that directly states the tool's function without unnecessary words. It's front-loaded with the core action ('Wait for') and lists the three waiting conditions clearly. There's no redundancy or fluff, making it highly concise and well-structured for quick understanding.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (3 parameters, no output schema) and rich annotations, the description is adequate but has gaps. It covers the basic purpose but lacks details on return values, error cases, or how it integrates with other browser tools. With no output schema, the description should ideally hint at what happens after waiting, but it doesn't, leaving completeness at a minimal viable level.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, with clear descriptions for all three parameters (time, text, textGone). The description adds minimal value beyond the schema by mentioning the parameters' purposes in a general way. Since the schema already documents parameters well, the baseline score of 3 is appropriate, as the description doesn't provide additional syntax, constraints, or usage examples.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose as waiting for text to appear/disappear or for time to pass, which is specific and actionable. It distinguishes itself from sibling tools like browser_click or browser_navigate by focusing on waiting/observation rather than interaction or navigation. However, it doesn't explicitly mention the browser context, which is implied but could be more precise.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for waiting scenarios but doesn't explicitly state when to use this tool versus alternatives. For example, it doesn't clarify if this should be used before browser_click or after browser_fill_form. There's no guidance on prerequisites or exclusions, leaving usage context to inference rather than explicit instruction.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/lewisvoncken/playwright-mcp'

If you have feedback or need assistance with the MCP directory API, please join our Discord server