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

With no annotations provided, the description must carry the full behavioral disclosure burden. It only reveals that no browser is launched, but it does not explain whether the check makes network requests, what side effects might occur, what the return value is, or how the many 'discarded' parameters behave.

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 no filler words. The two sentences both earn their place: the main purpose and the key 'no browser' caveat. However, the brevity borders on under-specification given the tool's nine-parameter schema.

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 heterogeneous optional parameters, no annotations, and no output schema, the description is incomplete. It does not explain what 'can be opened' means, how the other parameters relate to the check, or what an agent should expect as a result.

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?

Schema description coverage is 100%, so the schema already documents each parameter. The description adds no parameter-level meaning beyond that, meeting the baseline but not compensating for the apparent mismatch between the URL-focused description and the broad set of unrelated parameters such as city, json, and zone.

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', which is more informative than a mere label. The qualifier 'No browser is launched' adds a useful distinguishing detail, though it does not explicitly differentiate the tool from siblings like browser-url-ok or fetch-status.

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 versus alternatives such as browser-url-ok, fetch-status, or web-fetch. The statement does not mention conditions, exclusions, or preferred use cases, leaving the agent to infer applicability from the name alone.

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