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

The description reveals that no browser is launched, but it omits critical behavioral details: whether a network request is made, what 'opened' means, what failure modes exist, or what side effects may occur. With no annotations present, the description carries the full transparency burden.

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 concise and each sentence earns its place: the first states the purpose and the second adds a relevant constraint. However, it lacks structure to organize the nine optional parameters and would benefit from a brief note on their role.

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 no output schema and nine optional parameters, the description is severely incomplete. It does not specify what the tool returns, how 'ok' is determined, which parameters are relevant when, or how the parameters interact. This leaves an agent without essential information 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?

Although the schema has 100% per-parameter descriptions, those descriptions are inconsistent with the stated purpose (e.g., 'Git ref name; discarded after the shape check') and do not clarify how parameters like city, zone, or query relate to checking if a URL can be opened. The main description adds no parameter-level meaning.

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 states a clear action ('Check whether a URL can be opened') and a constraint ('No browser is launched'), but it does not explain how the many unrelated parameters (city, feed, json, zone, etc.) relate to this purpose, leaving the tool's actual scope ambiguous.

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?

There is no guidance on when to use this tool versus the many sibling tools like playwright-url-ok, fetch-status, or normalize-url. The only usage hint is 'No browser is launched', which is a behavioral constraint rather than usage guidance.

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