Advanced Tools

Tools for screenshots, JavaScript execution, and intelligent error analysis.

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screenshot

Capture a screenshot of the page or a specific element. Returns a base64-encoded PNG.

Parameters:

Name	Type	Required	Description
selector	string	No	Element to capture (default: full page)
fullPage	boolean	No	Capture full scrollable page (default: false)

Response:

{
  "image": "iVBORw0KGgoAAAANSUhEUgAA...",
  "format": "png",
  "width": 1280,
  "height": 720
}

Example:

Take a screenshot of the page
Capture a screenshot of just the header
Take a full-page screenshot including everything below the fold

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evaluate_js

Execute arbitrary JavaScript in the page context. Useful for:

• Reading page variables
• Triggering custom events
• Testing JavaScript logic
• Accessing browser APIs

Parameters:

Name	Type	Required	Description
script	string	Yes	JavaScript code to execute

Response:

{
  "result": { ... },
  "type": "object"
}

Example:

Execute: window.location.href
Execute: document.querySelectorAll('button').length
Execute: localStorage.getItem('authToken')
Execute: window.__REDUX_STORE__.getState()

Security Note: Be careful with scripts that modify page state during debugging.

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explain_error

Intelligent error analysis that combines multiple data sources to explain what went wrong and suggest fixes.

Parameters:

Name	Type	Required	Description
errorText	string	No	Specific error to focus on
includeNetwork	boolean	No	Include network context (default: true)
includeReact	boolean	No	Include React state (default: true)

Response:

{
  "error": {
    "type": "TypeError",
    "message": "Cannot read property 'user' of undefined",
    "location": "UserProfile.js:42",
    "stack": "..."
  },
  "context": {
    "console": [
      { "level": "error", "text": "..." }
    ],
    "network": [
      { "url": "/api/user", "status": 401 }
    ],
    "react": {
      "component": "UserProfile",
      "state": { "user": null }
    }
  },
  "analysis": {
    "category": "Data Access Error",
    "explanation": "The UserProfile component tried to access user.name but the user object is null. This likely happened because the /api/user request returned 401 Unauthorized.",
    "suggestions": [
      "Check if the user is authenticated before rendering UserProfile",
      "Add null checking: user?.name or user && user.name",
      "Investigate why the API returned 401 - check auth token"
    ]
  }
}

Example:

Explain the error on this page
What's causing the TypeError?
Analyze the errors with full context

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get_debug_summary

Get a quick overview of the page’s current state. Useful as a first step when starting a debugging session.

Parameters: None

Response:

{
  "url": "https://example.com/dashboard",
  "title": "Dashboard - MyApp",
  "status": {
    "errors": 2,
    "warnings": 3,
    "failedRequests": 1
  },
  "summary": {
    "hasErrors": true,
    "errorTypes": ["TypeError", "NetworkError"],
    "failedEndpoints": ["/api/user"],
    "reactDetected": true,
    "componentCount": 42
  }
}

Example:

Get a debug summary of this page
What's the current state? Any errors?
Give me an overview before I start debugging

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Common Patterns

Quick Health Check

Get a debug summary

Quickly see if there are errors, failed requests, or issues.

Deep Error Investigation

Get debug summary (overview)
Explain the error (detailed analysis)
Get console logs for more context
Show failed network requests

Visual Debugging

Take a screenshot to see the current state

Useful when layout issues can’t be described through DOM alone.

Custom Data Access

Execute: window.__APP_STATE__
Execute: JSON.parse(localStorage.getItem('user'))

Access application-specific data structures.

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Error Categories

The explain_error tool recognizes these error patterns:

Category	Examples
TypeError	Cannot read property, is not a function
Network	Failed to fetch, 4xx/5xx responses
CORS	Cross-origin request blocked
Syntax	Unexpected token, parsing errors
Reference	Variable is not defined
React	Invalid hook call, render errors
Promise	Unhandled rejection

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Tips

Start with Summary

Always start debugging sessions with get_debug_summary:

Get a debug summary to see what we're dealing with

Combine with Other Tools

Error analysis is most powerful when combined:

Explain the error
Show me the React component that crashed
Get the network request that failed

JavaScript for Edge Cases

When built-in tools don’t cover your case:

Execute: window.myApp.debugInfo()
Execute: document.cookie
Execute: performance.getEntriesByType('resource')

Screenshots for Visual Issues

Layout and styling issues need visual context:

Take a screenshot of the modal
The button looks wrong - take a screenshot

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