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

No annotations are provided, so the description carries the behavioral disclosure burden. It usefully discloses that no browser is launched, but does not state whether an HTTP request is made, what a positive or negative result looks like, or that several parameters are discarded.

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?

Two terse sentences deliver the core action and the key caveat with no filler. The main purpose is front-loaded and every phrase 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?

Given eight parameters, no annotations, and no output schema, the description is too sparse to fully support invocation. It does not identify which parameter is the meaningful one or what the check result means, leaving the discarded parameters only explained inside the schema.

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 input schema describes all eight parameters, including discard semantics for ref, json, and city, so schema coverage is high. The tool description adds no parameter-level meaning beyond what the schema already provides.

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 ('Check') and a target ('a URL'). The caveat 'No browser is launched' distinguishes it from sibling tools that may involve an actual browser, though it does not explain what 'opened' means operationally.

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 only usage signal is the implied lightweight nature of not launching a browser. There is no explicit when-to-use or when-not-to-use guidance, and no pointer to alternatives such as browser-url-ok or normalize-url.

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