Capture a full-page website screenshot as a PNG by submitting a page URL. Returns a job ticket for async rendering; poll with x402_poll_job to retrieve the result.
Full-page website screenshot as PNG, rendered on dedicated hardware ($0.05 USDC/call). ASYNC — returns a job ticket; poll with x402_poll_job (job_type 'box').
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | Page URL |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the async behavior, the return of a job ticket, the PNG output, the per-call cost, and the dedicated hardware rendering. It does not mention error handling or ticket expiration, but the essential behavioral contract is clear.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences with no wasted words. The first sentence delivers the core purpose and cost; the second provides the critical async polling procedure. The description is front-loaded and every clause earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a tool with one parameter and no output schema, the description is remarkably complete: it specifies the return (PNG), the async ticket, the polling sibling with its job_type argument, and the cost. An agent can correctly invoke and complete the workflow without additional information. The only minor omission is the structure of the job ticket, but that is not needed for correct invocation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema already documents the single URL parameter with 100% coverage. The description adds the nuance that the URL should be a full-page website, implying a web page rather than arbitrary content. This is marginal additional meaning above the schema, so the baseline of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description states a specific action: taking a full-page website screenshot and rendering it as PNG. It distinguishes from sibling tools like x402_image and x402_render by specifying 'full-page website' and the async job ticket pattern. The format (PNG) and cost are also included, making the purpose unmistakable.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description clearly explains the async workflow: call to get a job ticket, then poll x402_poll_job with job_type 'box'. This tells the agent the immediate next step and which sibling to use. It does not explicitly contrast with other screenshot-like tools (e.g., x402_render), but for a one-purpose tool this is sufficient.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.