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 does disclose a meaningful behavior ('No browser is launched'), but it does not explain whether network requests are made, what 'opened' means, possible failure modes, or any side effects. Partial transparency.

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 wasted words. The core purpose is front-loaded, and the key behavioral caveat follows immediately. Every word earns its place.

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 nine heterogeneous parameters (url, city, json, path, query, etc.) and no output schema, yet the description only addresses a narrow 'URL can be opened' case. It does not explain how the other parameters fit into the tool's behavior, what the result format is, or when this tool should be selected over similar siblings. Significant information is missing for an agent to confidently invoke it.

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%, so the schema already documents all nine parameters. The description adds no parameter-level meaning, but it does not need to compensate given the schema's completeness. Baseline 3 applies.

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's function: checking whether a URL can be opened. It is a specific verb+resource statement, and the added phrase 'No browser is launched' distinguishes it from siblings like playwright-url-ok, though it does not name the alternative explicitly.

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 description implies a lightweight check ('No browser is launched') but provides no explicit when-to-use or when-not-to-use guidance, nor does it reference alternatives such as fetch-status or normalize-url. The usage context is inferable but not stated.

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