Overview

The Tools feature is the heart of MCP Explorer—it’s designed for testing and debugging MCP server implementations. Execute tools, inspect responses, search JSON output, and auto-generate documentation.

Key Capabilities

✅ Browse All Tools

View all available tools from connected MCP servers

🔍 Search & Filter

Find tools quickly by name or description

⭐ Favorites

Mark frequently-used tools for instant access

🎯 Dynamic Parameters

Auto-generated forms based on tool input schemas

📋 Parameter Persistence

Previous values saved automatically for quick re-testing

🔎 Response Search

Search within JSON responses in real-time

📄 Auto-Generated Documentation

View complete tool schemas and parameter details

📑 Copy Tool Names

Click to copy tool names to clipboard for use elsewhere

Getting Started

Step 1: Connect to a Server

  1. Navigate to 🔌 Connections tab
  2. Select a connection
  3. Click Connect
  4. Return to 🛠️ Tools tab

📸 Screenshot needed: tools-tab-connected.png Description: Show the Tools tab with a connected server, displaying the list of available tools in the left sidebar

Step 2: Browse Available Tools

Once connected, you’ll see:

  • Tool list in the left sidebar
  • Tool count badge at the top
  • Search box for filtering
  • Favorite star icon for each tool

📸 Screenshot needed: tools-list-sidebar.png Description: Show the left sidebar with multiple tools listed, including some marked as favorites (with filled stars)

Step 3: Select a Tool

Click any tool to view its details in the main panel:

Tool information displayed:

  • Name: The tool identifier
  • Description: What the tool does
  • Input Schema: Expected parameters and types
  • Documentation: Auto-generated from schema

📸 Screenshot needed: tool-details-panel.png Description: Show a tool selected with its description, parameters section, and the “Call Tool” button visible

Executing Tools

Fill in Parameters

The parameter form is automatically generated from the tool’s input schema.

Supported parameter types:

  • String: Text input fields
  • Number: Numeric input fields
  • Boolean: Checkboxes
  • Enum: Dropdown selects
  • Object: Nested property fields
  • Array: Dynamic list items

📸 Screenshot needed: tool-parameters-form.png Description: Show a tool with multiple parameters filled in, demonstrating different input types (text, number, dropdown, checkbox)

info: Parameter Persistence: Your last used values are automatically saved and restored when you return to the same tool.

Call the Tool

  1. Fill in required parameters (marked with *)
  2. Fill in optional parameters as needed
  3. Click Call Tool button
  4. Watch for status indicator (loading spinner)
  5. View the response below

Execution flow:

Fill Parameters → Click "Call Tool" → Server Executes → Response Displayed

Working with Responses

View Formatted JSON

Responses are displayed as beautifully formatted, color-coded JSON.

Features:

  • Syntax highlighting (keys, strings, numbers, booleans, null)
  • Collapsible nested objects/arrays
  • Copy to clipboard
  • Fullscreen view

📸 Screenshot needed: tool-response-json.png Description: Show a tool response with formatted JSON, highlighting the color-coding and structure

Search Response Content

Use the search box at the top of the response viewer to filter JSON content in real-time.

Search behavior:

  • Matches keys and values
  • Highlights matching text
  • Case-insensitive
  • Instant filtering

Use cases:

  • Find specific error codes
  • Locate nested properties
  • Filter large response arrays
  • Debug specific fields

📸 Screenshot needed: tool-response-search.png Description: Show the response viewer with a search term entered and matching text highlighted in yellow

Fullscreen Mode

Click the fullscreen icon (⛶) in the response viewer toolbar to expand the JSON view.

Benefits:

  • Focus on response data
  • View deeply nested structures
  • Better readability for large responses
  • Press ESC or click again to exit

📸 Screenshot needed: tool-response-fullscreen.png Description: Show the fullscreen JSON viewer with a large response displayed

Advanced Features

Favorites Management

Mark tools you use frequently as favorites for quick access.

To add a favorite:

  1. Click the star icon (☆) next to a tool name
  2. Star fills in (★) to indicate it’s favorited

To view favorites only:

  1. Use the search/filter options (if available)
  2. Favorites appear at the top of the list

To remove a favorite:

  1. Click the filled star (★)
  2. Star empties (☆) to indicate it’s unfavorited

Copy Tool Names

Quickly copy tool names to use in code, documentation, or chat.

How to copy:

  1. Select a tool
  2. Click the copy icon (📋) or copy button
  3. Tool name is copied to clipboard
  4. Use in prompts, code, or other tools

Use cases:

  • Reference tools in chat messages
  • Document which tools were tested
  • Share tool names with team members
  • Use in scripts or automation

Parameter History

MCP Explorer remembers your last used values for each tool.

Behavior:

  • Values persist across sessions
  • Separate history per tool
  • Encrypted storage for sensitive values

Benefits:

  • Faster re-testing with same inputs
  • No need to re-enter common values
  • Streamlined debugging workflow

Auto-Generated Documentation

Each tool automatically displays its complete schema.

Documentation includes:

  • Tool name and description
  • Parameter names and types
  • Required vs optional fields
  • Enum values (for dropdowns)
  • Default values
  • Nested object/array structures

📸 Screenshot needed: tool-auto-documentation.png Description: Show a tool’s parameter section displaying the schema information, highlighting required fields and descriptions

Common Workflows

Testing a New Tool

  1. Connect to server
  2. Find tool in list or use search
  3. Read the auto-generated documentation
  4. Fill in minimal required parameters
  5. Execute and inspect response
  6. Adjust parameters and re-test
  7. Mark as favorite if frequently used

Debugging Tool Behavior

  1. Execute tool with known-good parameters
  2. Inspect the JSON response structure
  3. Use search to find specific error codes or fields
  4. Modify parameters to test edge cases
  5. Compare responses between executions
  6. Copy tool name for reference in bug reports

Building Tool Call Chains

  1. Execute first tool to get data
  2. Copy relevant values from response
  3. Select second tool
  4. Paste values into parameters
  5. Execute and verify chained behavior

Troubleshooting

Tool List is Empty

Problem: No tools appear after connecting

Solutions:

  1. Verify server is actually connected (check status indicator)
  2. Ensure the server implements MCP tools capability
  3. Check server logs for errors
  4. Disconnect and reconnect

Tool Execution Fails

Problem: Error message or timeout when calling tool

Solutions:

  1. Verify all required parameters are filled
  2. Check parameter value types match schema
  3. Review server logs for detailed errors
  4. Test with minimal/default parameters first
  5. Check authentication headers are correct

Response Not Displaying

Problem: Tool executes but no response shown

Solutions:

  1. Check browser console for JavaScript errors
  2. Verify tool actually returns data
  3. Test with a simpler tool first
  4. Clear browser cache and reload

Parameters Not Saving

Problem: Parameter history doesn’t persist

Solutions:

  1. Ensure browser allows localStorage
  2. Check that settings file is writable
  3. Verify you’re using same browser profile
  4. Review console for permission errors

Tips & Best Practices

🎯 Use Favorites

Mark your most-used tools to save time navigating large tool lists.

🔍 Search First

Use the search box before scrolling through long tool lists.

📋 Keep Test Data

Save sample parameter values in a separate document for quick copy/paste testing.

🔄 Test Edge Cases

Try empty strings, null values, and boundary conditions to verify server validation.

📸 Screenshot Responses

Capture important responses for documentation or bug reports.

🔗 Chain Tools

Use output from one tool as input to another to test complex workflows.

Next Steps