Skip to main content
Glama

analyze_webpage_screenshot

Extract content, layout, and interactive elements from webpage screenshots to analyze structure and accessibility.

Instructions

Specialized tool for analyzing webpage screenshots. Extracts content, layout information, and interactive elements from web pages.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
typeYesThe type of image input
dataYesThe webpage screenshot data (base64 string, file path, or URL)
mimeTypeNoMIME type of the image (required for base64 input)
focusAreaNoSpecific area to focus on (optional)
includeAccessibilityNoInclude accessibility analysis (default: true)
formatNoOutput format (default: json for structured webpage analysis)
maxTokensNoMaximum tokens in response (default: 4000)

Implementation Reference

  • The handler function that processes the input arguments, handles image processing, constructs specialized prompts for webpage screenshot analysis (including focus areas like layout, content, accessibility), calls the OpenRouter vision model API, and returns the analysis result.
    export async function handleAnalyzeWebpage(
      args: any,
      config: Config,
      openRouterClient: OpenRouterClient,
      logger: Logger
    ) {
      const imageProcessor = ImageProcessor.getInstance();
    
      try {
        const imageInput = {
          type: args.type as 'base64' | 'file' | 'url',
          data: args.data as string,
          mimeType: args.mimeType as string,
        };
    
        const focusArea = args.focusArea as string;
        const includeAccessibility = args.includeAccessibility !== false;
        const format = args.format as 'text' | 'json' || 'json';
        const maxTokens = args.maxTokens as number || 4000;
    
        logger.info(`Starting webpage screenshot analysis for type: ${imageInput.type}, focus: ${focusArea}`);
    
        // Process the image
        const processedImage = await imageProcessor.processImage(imageInput);
    
        // Validate image type
        if (!imageProcessor.isValidImageType(processedImage.mimeType)) {
          throw new Error(`Unsupported image type: ${processedImage.mimeType}`);
        }
    
        // Check file size
        const serverConfig = config.getServerConfig();
        const maxImageSize = serverConfig.maxImageSize || 10485760;
        if (processedImage.size > maxImageSize) {
          throw new Error(`Image size ${processedImage.size} exceeds maximum allowed size ${maxImageSize}`);
        }
    
        // Build specialized prompt for webpage analysis
        let prompt = 'Analyze this webpage screenshot and provide detailed information about its structure, content, and design.';
    
        if (focusArea) {
          switch (focusArea) {
            case 'layout':
              prompt += ' Focus specifically on the layout structure, grid system, spacing, and visual hierarchy.';
              break;
            case 'content':
              prompt += ' Focus specifically on the content, headings, body text, and information architecture.';
              break;
            case 'navigation':
              prompt += ' Focus specifically on navigation elements, menus, breadcrumbs, and user pathways.';
              break;
            case 'forms':
              prompt += ' Focus specifically on form elements, input fields, buttons, and validation indicators.';
              break;
            case 'interactive':
              prompt += ' Focus specifically on interactive elements like buttons, links, hover states, and calls-to-action.';
              break;
            case 'accessibility':
              prompt += ' Focus specifically on accessibility features, contrast ratios, alt text indicators, and keyboard navigation.';
              break;
          }
        }
    
        prompt += ' Include specific details about:';
    
        if (includeAccessibility || focusArea === 'accessibility') {
          prompt += ' accessibility considerations, color contrast, font sizes, and assistive technology compatibility;';
        }
    
        prompt += ' responsive design indicators, viewport information, and mobile optimization; visual design elements like colors, typography, and branding; user experience considerations and potential usability issues; any errors, warnings, or unusual states visible.';
    
        if (format === 'json') {
          prompt += ' Provide your analysis in a structured JSON format with the following schema: {"page_title": "string", "url": "string (if visible)", "layout": {"header": "description", "navigation": "description", "main_content": "description", "sidebar": "description", "footer": "description"}, "content": {"headings": ["list"], "body_text": "summary", "key_elements": ["list"]}, "interactive_elements": {"buttons": ["list"], "links": ["list"], "forms": ["list"]}, "design": {"color_scheme": "description", "typography": "description", "branding": "description"}, "accessibility": {"score": "1-10", "issues": ["list"], "positive_aspects": ["list"]}, "usability": {"strengths": ["list"], "issues": ["list"], "recommendations": ["list"]}, "technical_notes": "technical observations"}';
        }
    
        // Analyze the webpage screenshot
        const result = await openRouterClient.analyzeImage(
          processedImage.data,
          processedImage.mimeType,
          prompt,
          { format, maxTokens }
        );
    
        if (!result.success) {
          throw new Error(result.error || 'Failed to analyze webpage screenshot');
        }
    
        logger.info(`Webpage screenshot analysis completed successfully`, {
          model: result.model,
          usage: result.usage,
        });
    
        return {
          content: [
            {
              type: 'text',
              text: result.analysis || 'No analysis available',
            },
          ],
        };
      } catch (error) {
        logger.error('Webpage screenshot analysis failed', error);
        return {
          content: [
            {
              type: 'text',
              text: `Error: ${(error as Error).message}`,
            },
          ],
          isError: true,
        };
      }
    }
  • Input schema definition for the analyze_webpage_screenshot tool, specifying parameters like image type, data, focus areas, format, etc.
    inputSchema: {
      type: 'object',
      properties: {
        type: {
          type: 'string',
          enum: ['base64', 'file', 'url'],
          description: 'The type of image input',
        },
        data: {
          type: 'string',
          description: 'The webpage screenshot data (base64 string, file path, or URL)',
        },
        mimeType: {
          type: 'string',
          description: 'MIME type of the image (required for base64 input)',
        },
        focusArea: {
          type: 'string',
          enum: ['layout', 'content', 'navigation', 'forms', 'interactive', 'accessibility'],
          description: 'Specific area to focus on (optional)',
        },
        includeAccessibility: {
          type: 'boolean',
          description: 'Include accessibility analysis (default: true)',
        },
        format: {
          type: 'string',
          enum: ['text', 'json'],
          description: 'Output format (default: json for structured webpage analysis)',
        },
        maxTokens: {
          type: 'number',
          description: 'Maximum tokens in response (default: 4000)',
        },
      },
      required: ['type', 'data'],
    },
  • src/index.ts:90-130 (registration)
    Tool registration in the listTools handler, defining name, description, and input schema.
    {
      name: 'analyze_webpage_screenshot',
      description: 'Specialized tool for analyzing webpage screenshots. Extracts content, layout information, and interactive elements from web pages.',
      inputSchema: {
        type: 'object',
        properties: {
          type: {
            type: 'string',
            enum: ['base64', 'file', 'url'],
            description: 'The type of image input',
          },
          data: {
            type: 'string',
            description: 'The webpage screenshot data (base64 string, file path, or URL)',
          },
          mimeType: {
            type: 'string',
            description: 'MIME type of the image (required for base64 input)',
          },
          focusArea: {
            type: 'string',
            enum: ['layout', 'content', 'navigation', 'forms', 'interactive', 'accessibility'],
            description: 'Specific area to focus on (optional)',
          },
          includeAccessibility: {
            type: 'boolean',
            description: 'Include accessibility analysis (default: true)',
          },
          format: {
            type: 'string',
            enum: ['text', 'json'],
            description: 'Output format (default: json for structured webpage analysis)',
          },
          maxTokens: {
            type: 'number',
            description: 'Maximum tokens in response (default: 4000)',
          },
        },
        required: ['type', 'data'],
      },
    },
  • src/index.ts:194-195 (registration)
    Dispatch/registration of the handler in the centralized CallToolRequestSchema switch statement.
    case 'analyze_webpage_screenshot':
      return await handleAnalyzeWebpage(args, config, openRouterClient, logger);
  • src/index.ts:13-13 (registration)
    Import of the handler function.
    import { handleAnalyzeWebpage } from './tools/analyze-webpage.js';

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observed

TDQS

B3.2/5.0
Behavior2/5

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It only states what the tool extracts but omits details about processing, privacy, size limits, or output structure beyond what the schema implies.

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 highly concise with two sentences, front-loading the core purpose. No unnecessary words.

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

Completeness2/5

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

Given 7 parameters and no output schema or annotations, the description lacks important behavioral context such as input constraints, output format details, or handling of optional parameters. It is insufficient for an agent to reliably use the tool.

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?

The schema covers 100% of parameters with descriptions, so the description adds limited value beyond stating the extraction focus. Baseline 3 is appropriate as the schema does the heavy lifting.

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 is for analyzing webpage screenshots and extracting content, layout, and interactive elements. However, it does not explicitly differentiate from sibling tools like analyze_image or analyze_mobile_app_screenshot, leaving the agent to infer the scope.

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 that this tool is specialized for webpages, suggesting it should be used over the general analyze_image for that context. However, it provides no explicit when-to-use or when-not-to-use guidance, nor does it name alternatives.

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