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

With no annotations provided, the description carries the full burden of disclosing behavior. It only says 'No browser is launched,' but does not explain whether network access occurs, how failures are reported, whether any side effects happen, or what the tool actually does to determine URL openness.

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 extremely concise and contains no filler or redundant wording. It delivers the core action and an important constraint in just two short sentences.

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?

The definition lacks essential context for correct invocation given its complexity: no output schema, no explanation of return values, no indication which of the nine optional parameters are relevant, and no guidance on how the parameters relate to the stated URL-checking purpose.

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?

Although the schema has 100% description coverage, the parameter descriptions are incoherent relative to the tool's stated purpose. The url parameter is described as 'HTTPS URL to normalize or cite' rather than something to check, and most other parameters (city, zone, query, ref) are unrelated to checking whether a URL can be opened.

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 action and resource: check whether a URL can be opened, and adds the constraint that no browser is launched. However, the purpose is undermined by the input schema, which contains nine unrelated optional parameters (city, zone, query, etc.) that do not align with checking a URL.

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 gives almost no guidance on when to use this tool instead of alternatives. Sibling tools like fetch-status, normalize-url, and playwright-url-ok likely overlap, but no distinctions or explicit use conditions are provided beyond the single note that no browser is launched.

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