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

With no annotations, the description carries full responsibility for disclosing side effects. It states that no browser is launched and some parameter descriptions say values are discarded, but it does not disclose whether a network request is made, what statuses are treated as 'ok,' or what side effects or errors may occur.

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 main description is very short, front-loaded, and free of filler: two sentences convey the core check and the no-browser caveat. It loses a point only because it omits enough context to make the concise wording unambiguous.

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?

For a tool with nine optional parameters and no output schema, the description is not complete enough to predict behavior. It does not explain what 'can be opened' means, how the check is performed, which parameters are actually used, or what result is returned.

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 inconsistent with the stated purpose: 'url' is described as 'HTTPS URL to normalize or cite' rather than to open, and seven other optional parameters appear irrelevant to URL checking. The tool description does not explain how these parameters relate to 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 names an action and resource ('Check whether a URL can be opened') and adds a key caveat ('No browser is launched'), but 'opened' is ambiguous and the description does not align with the nine-input schema, many of which are unrelated to URLs.

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 about when to use this tool instead of siblings such as browser-url-ok, fetch-status, or web-fetch. The only behavioral note is 'No browser is launched,' which does not explain the intended selection context.

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