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

With no annotations provided, the description carries the full behavioral disclosure burden. It only reveals that no browser is launched, but does not clarify whether a network request occurs, what 'can be opened' means, whether there are side effects, or what the tool returns. This is a significant transparency gap.

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: purpose first, then a key behavioral constraint. However, the brevity is not fully appropriate for a 9-parameter tool with broader scope than just URL checking, so it earns a high but not perfect score.

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 no annotations and no output schema, the description is too thin to be contextually complete. It does not describe the result format, how non-URL parameters are handled, or what the tool actually does besides not launching a browser. An agent cannot fully predict call behavior from this 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 all nine parameters are already documented in the schema. The description adds no parameter-specific meaning beyond implying that the URL check does not launch a browser. Baseline 3 is appropriate because the schema handles parameter semantics.

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?

States a specific verb and resource: checking whether a URL can be opened. The 'No browser is launched' qualifier adds useful distinction from browser-based checks. However, it omits the tool's other accepted input kinds (city, JSON, path, zone, query) and does not explicitly differentiate 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 the many sibling tools. 'No browser is launched' implies a lightweight check, but the description does not mention alternatives, exclusions, or conditions that would help an agent choose between this tool and web-fetch, fetch-status, normalize-url, or browser-url-ok.

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