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

No annotations are provided, so the description carries the full burden. It discloses one useful behavior ('No browser is launched') but omits whether the check performs a network request, what 'can be opened' means, whether it is read-only, or whether any permissions or side effects are involved. This is only partial disclosure.

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 the primary action front-loaded and the clarifying negative immediately after. Every word earns its place; there is no filler, repetition, or unnecessary detail.

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?

With 9 parameters, no annotations, and no output schema, this definition is too sparse. It does not state the return value, which parameter an agent should supply, or how 'can be opened' is determined. The rich schema descriptions help, but an agent would still be guessing about invocation and behavioral expectations.

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 the baseline is 3. The description adds no parameter-level meaning beyond the schema, but the schema itself already documents each parameter, including the fact that many values are discarded after the check. No adjustment is needed.

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 a specific action ('Check whether a URL can be opened') and adds a distinguishing behavioral note ('No browser is launched'), which separates it from browser-launching siblings like playwright-url-ok. However, it does not explicitly name sibling tools or reconcile the URL-focused purpose with the many non-URL parameters 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 this is a lightweight non-browser check, giving some usage context. But it does not explicitly say when to use this tool over alternatives like normalize-url, fetch-status, or playwright-url-ok, nor does it state when not to use it.

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