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

The description discloses one important behavioral trait (no browser launch) but omits other details such as what 'can be opened' means, side effects, permissions, or error behavior. Since no annotations are provided, the description bears the full burden, and this minimal disclosure is only partially transparent.

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 a single, direct sentence with no unnecessary words. It fully conveys the core action and a key constraint in a compact form.

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 tool's complexity (9 parameters, no output schema, no annotations), the description is severely incomplete. It does not explain what 'can be opened' entails, how the multiple parameters are used, or what the expected return value or error behavior is. The mismatch between the URL-focused description and the broad parameter set leaves agents without enough context to invoke the tool correctly.

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 descriptions cover 100% of the 9 parameters, but the tool description adds no clarification about how parameters relate to the URL check. Many parameter descriptions ('discarded after the shape check') suggest they are irrelevant to the stated purpose, and the description does not resolve this ambiguity.

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 tool checks whether a URL can be opened and explicitly notes that no browser is launched, which differentiates it from the sibling 'browser-url-ok' tool. However, it does not name the alternative explicitly and the purpose is slightly undermined by the unrelated parameter descriptions in the schema.

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 a lightweight check and suggests when to use this over the browser-launching sibling, but it does not explicitly state usage conditions or contrast with alternatives. The parameter schema further confuses usage by including fields like city, zone, and query that are unrelated to URL checking.

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