Inspect, test, and evaluate WebMCP tool implementations on any website.
Users
9
0 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
3
0 in 30 days
Store rank
#199K
#166K among extensions
Version
1.0.5
updated 8 Sep 2026
Users
monthly, 2 months
Latest, 16 Oct 2026:9 usersMove the mouse over the chart for any month
Ratings count
monthly, 2 months
Latest, 16 Oct 2026:3 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About WebMCP Lens
WebMCP Lens gives you a clear, real-time view of every WebMCP tool exposed by a website — including its definition, schema, availability, execution results, and AI tool-selection performance.
Instead of switching between code, logs, prompts, and separate testing tools, you can review the entire WebMCP implementation from one browser side panel.
1. Everything You Need to Test WebMCP
🔎 Discover and inspect tools
Automatically detects all tools registered by the current page, including tools added or removed dynamically after the page loads.
View:
- Tool names and descriptions
- Input and output schemas
- Current availability
- Complete tool definitions in a readable format
▶️ Invoke tools directly
Test any exposed tool using:
- A natural-language prompt with Try a Prompt
- A generated input form
- Raw JSON
📡 Live logging
See WebMCP activity as it happens:
- Tool registrations
- Status changes
- Tool-list requests and responses
See the response, execution status, duration, and errors immediately.
No separate test page. No digging through console output.
2. Evaluate Whether AI Can Actually Use Your Tools
A valid tool is not necessarily a tool an AI model will understand correctly.
Create evaluation suites to check whether an AI model can:
- Understand the request
- Select the correct tool
- Generate the right arguments
- Avoid incorrect or forbidden tools
- Behave consistently across repeated runs
Review tool-selection accuracy, argument matching, consistency, and invalid model responses from one dashboard.
3. Find Problems Before They Reach Production
Run a one-click audit across:
- Definitions
- Schemas
- Tool-set design
- Safety
WebMCP Lens highlights errors, warnings, recommendations, and passed checks, helping you quickly identify unclear descriptions, broken schemas, overlapping tools, unsafe actions, and other common implementation problems.
4. Build Repeatable Tests
Save any invocation as a reusable functional test.
Run individual tests or complete test suites after website updates to confirm that tools still accept the expected inputs and return the right results.
It turns one-off debugging into repeatable QA.
5. Private by Design
No analytics.
No tracking.
No external storage.
All extension data stays locally on your device.
The only optional network request occurs when you choose Gemini Cloud evaluations and provide your own API key. Nothing is sent to the extension developer.
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WebMCP Lens helps you move from:
“The tools are registered.”
to:
“The tools work, pass QA, and can be used reliably by AI agents.”
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Built by SWC Consulting
A digital analytics and data technology consultancy focused on serious measurement infrastructure.