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

With no annotations provided, the description must carry the behavioral disclosure burden. It mentions 'No browser is launched,' which is a useful non-obvious detail, but it does not disclose what the tool does with the various inputs, whether any side effects occur, or what it returns. This is inadequate for a tool with 9 optional parameters.

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 very short (two sentences), which is concise, but given the complexity of 9 parameters, it is under-specified. The core purpose is front-loaded, yet the brevity leaves out essential context about how the parameters are used, making it borderline under-specification rather than efficient conciseness.

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 9 optional parameters and no output schema, the description is incomplete. It does not explain how each parameter contributes to the check, what 'can be opened' means for different input types, or what the tool returns. The complexity demands far more context than provided.

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 coverage is 100% because every parameter has a description (e.g., 'discarded after the check'), so the schema already documents parameters. The tool description adds no additional meaning beyond the schema, which gives a baseline of 3. It neither reinforces nor enriches the parameter information.

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 verb and resource ('check whether a URL can be opened') but is ambiguous because the input schema contains 9 unrelated parameters (city, json, path, zone, etc.). It fails to clarify how these relate to the stated purpose, making the tool's actual scope unclear despite not being a tautology.

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 provided on when to use this tool versus alternatives like browser-url-ok or fetch-status. The description offers no exclusions, prerequisites, or context for choosing it over sibling tools.

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