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

With no annotations, the description must disclose behavioral traits. It does state 'Page content is not stored,' which is a useful privacy note. However, it fails to explain side effects, network behavior, rate limits, or how the 'discarded' parameters behave in practice. Many parameters are described as 'discarded after the check,' implying they have no lasting effect, but this is not aggregated or clarified. The description is far from sufficient for a tool with this many behaviors.

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, front-loaded sentence that immediately states the primary function and a key behavioral caveat. It is concise and to the point. However, it is so brief that it omits essential context about the broader parameter set, making it under-specified rather than efficiently concise. It earns a 4 for structure but not a 5 because it sacrifices completeness for brevity.

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, and no annotations), the description is grossly incomplete. It does not explain what happens when non-URL parameters are provided, what the return value looks like for those cases, or how the tool differs from its many siblings. An agent cannot safely call this tool correctly for anything beyond the URL case. The absence of an output schema places a heavier burden on the description, which it fails to meet.

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?

Schema description coverage is 100%, so each parameter already has a description. The tool description adds no value beyond the schema, not even a summary of the parameter groups or which one to provide. Since the schema covers all parameters, the baseline is 3, but the description could have enhanced understanding by explaining how parameters relate to the main purpose (e.g., that each triggers a different check). It doesn't, so a 3 is fair.

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 verb and resource: 'Return host, scheme, and HTTP status for a URL.' This is clear and actionable. However, it doesn't differentiate from sibling tools like fetch-status or normalize-url, and it ignores the nine optional parameters in the schema, making the tool's full purpose ambiguous. The single-sentence focus on URL checking suggests a narrower scope than the schema implies.

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?

No guidance is given on when to use this tool versus siblings such as fetch-status, normalize-url, or web-fetch. The description does not mention any conditions, prerequisites, or alternatives, leaving the agent to guess which tool fits a given task. With 27 sibling tools, explicit routing is essential.

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