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 side effects and behavior. It only states that no browser is launched, but does not mention whether a network request is made, whether the tool can fail, or any side effects or limitations.

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, with no redundant or irrelevant content. It efficiently communicates the core action and a key behavioral constraint in a single sentence.

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 high parameter count and absence of an output schema, the description is incomplete. It does not explain what the check returns, how success or failure is represented, or which parameters are relevant, making it difficult for an agent to use the tool correctly.

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 schema description coverage is 100%, the parameter descriptions are inconsistent with the tool's stated purpose. The 'url' parameter is described as 'HTTPS URL to normalize or cite' rather than a URL to check, and most other parameters are described as discarded, leaving it unclear which input is actually used for the 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 clearly states the primary action: checking whether a URL can be opened, and adds a useful negative constraint that no browser is launched. However, it does not fully distinguish from sibling tools such as browser-url-ok or fetch-status, which likely perform similar reachability checks.

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 about when to use this tool versus alternatives like browser-url-ok, fetch-status, or web-fetch. It also does not specify which input parameter is required or how the tool should be invoked.

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