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

The description adds a useful behavioral guarantee: 'Page content is not stored.' With no annotations present, this partially compensates for the lack of safety cues. However, it does not disclose whether a network request is made, whether results are cached, or how the many other input fields are handled.

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 two short sentences with no filler. The primary behavior is front-loaded, and the second sentence earns its place by adding a meaningful privacy/storage guarantee.

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?

Despite a small description, the tool has 9 parameters, no output schema, no annotations, and many closely related sibling tools. The description lacks selection guidance, output format details, and any explanation of the broader parameter set, making it insufficient for reliable 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 input schema already describes all 9 parameters with 100% coverage, so the baseline is 3. The description adds little beyond mentioning a 'URL,' and it does not explain the purpose of the other parameters like ref, city, feed, json, or path. It also uses 'host' as both an output term and an input parameter, which could create mild ambiguity.

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 operation: 'Return host, scheme, and HTTP status for a URL.' This identifies the verb, resource, and expected outputs. However, it does not differentiate this tool from siblings like normalize-url or fetch-status that likely overlap in behavior.

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 provides no guidance on when to use this tool versus alternatives such as fetch-status, normalize-url, or browser-url-ok. It neither states conditions for use nor names exclusions or sibling tools.

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