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

The description discloses that no browser is launched, but it does not explain what 'ok' means, what side effects or network effects may occur, what failure modes exist, or what the return value looks like. Since there are no annotations and no output schema, the description carries the full transparency burden and does not meet it.

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 short and front-loaded with the core action, but it omits necessary structural detail such as return format, error behavior, and parameter relevance. It is concise in word count but not well-formed as a functional tool description.

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 input schema has nine parameters and no output schema, the description is severely incomplete. It does not clarify which parameters are required or meaningful, what the tool returns, how success is determined, or how this tool relates to nearby siblings such as fetch-status and playwright-url-ok.

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 schema contains nine parameters, but only url is plausibly relevant to checking whether a URL can be opened, and even its description says to normalize or cite it rather than open it. The other eight parameters—ref, city, feed, json, path, zone, query—are unrelated and described as discarded or checked for shape, creating severe semantic noise and misleading an agent.

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 single action—check whether a URL can be opened—but leaves 'can be opened' undefined in terms of HTTP status, reachability, or browser compatibility. It also conflicts with the url parameter description, which says the URL is 'to normalize or cite' rather than to open.

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 only usage guidance is 'No browser is launched,' which is a constraint rather than guidance on when to use this tool versus sibling tools like fetch-status, normalize-url, or playwright-url-ok. There is no mention of appropriate contexts, prerequisites, or expected caller intent.

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