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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only says no browser is launched; it does not explain whether a network request is made, what 'can be opened' means, whether there are side effects, what statuses are considered acceptable, or what output the agent should expect.

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 two short sentences with no filler. The core action is stated first, and the key behavioral constraint 'No browser is launched' is included immediately, making it easy to parse and act on.

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 tool has 9 optional parameters, no output schema, no annotations, and many siblings, yet the description does not explain what the output looks like, how parameters are used, or what 'opened' means in practice. This is too sparse for an agent to confidently invoke the tool in varied scenarios.

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 parameters are individually documented. The tool description itself adds no parameter-specific meaning, and the relationship between the URL check and parameters like city, json, or path is unclear, but the schema descriptions provide enough baseline information for a score of 3.

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 action as checking whether a URL can be opened and explicitly notes that no browser is launched, which helps distinguish it from browser-based sibling tools. However, the input schema includes many unrelated parameters like city, json, path, and zone, so the true scope of the tool is somewhat ambiguous from the description alone.

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 phrase 'No browser is launched' implies this tool is appropriate when a lightweight, browserless URL checks is needed, but no explicit when-to-use or when-not-to-use guidance is provided. It does not name alternatives such as browser-url-ok or fetch-status, leaving the selection logic mostly to inference.

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