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

With no annotations, the description must carry the burden of behavioral disclosure. It does disclose that 'Page content is not stored,' which is useful, but it says nothing about side effects of the other parameters, whether network requests are made, or how the tool treats the non-URL fields. For a tool with this many parameters, the behavioral transparency is minimal.

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 a single sentence that is easy to parse and front-loads the core function. It is appropriately short, though it omits necessary context about the other parameters. Conciseness itself is good, but the brevity contributes to the incompleteness.

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?

Given the tool's complexity (9 parameters, no output schema, many siblings), the description is severely incomplete. It does not explain the purpose of the extra parameters, how the output is formatted beyond three fields, or how it differs from overlapping tools. An agent cannot confidently call this tool correctly with only the provided description.

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 input schema has 100% coverage, so each parameter has a description, satisfying the baseline of 3. However, the tool description adds no extra meaning beyond the schema – it only mentions 'URL' while the schema describes the other parameters as discarded or validated. The description does not clarify how these parameters relate to the stated output, so it neither helps nor harms beyond the baseline.

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 clear core action – 'Return host, scheme, and HTTP status for a URL' – but the input schema includes 9 parameters, many of which (city, zone, json, path) have nothing to do with URLs. The description gives no hint of what these parameters do, making the tool's actual scope ambiguous and potentially misleading an agent into thinking it only accepts a URL when it accepts many other inputs.

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?

There is no guidance about when to use this tool versus the many siblings (e.g., normalize-url, fetch-status, browser-url-ok). No mention of alternatives, no exclusions, no contextual triggers. An agent cannot distinguish this tool's appropriate use case from overlapping tools.

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