Inspect a public URL: HEAD redirect trace, DNS A/AAAA observations and security headers in one report. At most 4 targets, no page body. Includes timestamps, partial-result warnings and factual findings; no safety or reputation verdict. Paid per call: $0.009 in USDC via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | One public HTTP(S) URL on its standard port; credentials and private destinations are rejected |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of disclosing behavior. It fully discloses that it is paid per call ($0.009 USD via x402), processes at most 4 targets, does not fetch body content, and includes timestamps and partial-result warnings. This exceeds the minimal expectations and provides key operational details.
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?
The description is concise and front-loaded with the main purpose, followed by critical constraints and pricing. Each sentence adds value, covering scope, limitations, and costs without redundancy.
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 single-parameter tool, the description is complete: it explains what is included (HEAD trace, DNS observations, security headers), what is not (page body, safety verdict), and the operational constraints (max targets, cost, timestamps). No output schema exists, but the description adequately sets expectations for the report contents.
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 parameter url is fully documented in the schema with a detailed description of constraints (e.g., public URL, standard port, rejects credentials). The tool description adds no additional parameter-specific semantics beyond what the schema already states, so the baseline 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 clearly states the tool's purpose: inspecting a public URL and reporting on redirect trace, DNS observations, and security headers, explicitly excluding page body content and safety verdicts. It distinguishes itself from siblings like dns and extract by specifying the combined report nature.
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?
While it doesn't explicitly name alternative tools, it clearly describes what the tool does not do (no page body, no safety or reputation verdict), implying when not to use it. The context of what it inspects makes it distinct from siblings like dns or extract, providing practical guidance for selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
