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

With no annotations, the description carries the transparency burden, but it only reveals that no browser is launched. It does not disclose whether the tool makes a network request, what 'can be opened' means, what side effects occur, or what the return value looks like.

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 clear sentence and is not padded. The schema is compact and well-structured, with no redundant prose.

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 description does not explain the return format, failure behavior, or how the many optional parameters relate to the stated purpose. Given nine optional parameters and no output schema, the tool is under-specified for reliable use.

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 every parameter has a schema description, many descriptions are unrelated or contradictory to the tool purpose: 'url' is described as 'HTTPS URL to normalize or cite,' and city/feed/json/zone/query parameters are labeled 'discarded' or irrelevant. An agent cannot confidently determine which parameter to supply for the URL check.

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 action and resource: 'Check whether a URL can be opened.' The additional clause 'No browser is launched' clarifies the check is non-browser and differentiates from sibling browser-based tools like playwright-url-ok.

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 does not specify when to use this tool instead of alternatives such as normalize-url, fetch-status, or playwright-url-ok. The only hint is 'No browser is launched,' which weakly implies a lightweight check, but no explicit use cases or exclusions are given.

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