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

No annotations are provided, so the description must convey all important behavioral traits. It only states that no browser launches, but it does not say whether a network request is made, what output is produced, whether permissions are needed, or if there are side effects. This leaves the tool's behavior largely undisclosed for the agent.

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 concise, front-loading the core action and then adding the important 'no browser' behavioral nuance. Each sentence earns its place, but for a tool with 9 parameters some additional structure would have been appropriate.

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?

With 9 optional parameters, no output schema, and no explanation of how the parameters are used or discarded, the description is too sparse to let an agent know exactly how the tool behaves or what it returns. An agent would not be able to confidently call this tool correctly based on description alone.

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 already well documented by the schema. The tool description adds no extra parameter context and does not reconcile why city, zone, json, and feed are included in a 'URL openable' check, but the baseline of 3 applies because the schema itself covers the missing detail.

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, 'Check whether a URL can be opened,' and the second sentence, 'No browser is launched,' helps differentiate it from browser-launching siblings like browser-url-ok. However, the nine-parameter schema contains many unrelated inputs (city, zone, json, path, etc.), which adds ambiguity to the tool's true purpose.

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 'No browser is launched' sentence subtly implies use for lightweight checks, but there is no explicit when-to-use, when-not-to-use, or mention of alternative sibling tools. Usage guidance is left mostly to inference from the tool name and this one behavioral note.

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