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

Discloses that no browser is launched but does not describe the actual mechanism (e.g., HTTP request, DNS check) or side effects, leaving the behavior opaque.

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 a single, succinct sentence; the schema is well-structured, though the parameter descriptions are nonsensical.

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?

Lacks essential details such as return value, error behavior, example outputs, or how the parameters are used; the tool is underspecified for an agent to invoke 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?

All nine parameters have descriptions that are unrelated to checking URL openability (e.g., city, zone, json) and appear to be copied from other tools; they provide no coherent meaning for this tool.

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 verb and object for checking URL openability, but the input schema includes unrelated parameters that obscure the intended usage, so purpose clarity is only moderate.

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?

Provides no explicit guidance on when to use this tool versus siblings like browser-url-ok or fetch-status; the 'No browser is launched' hint is implicit but not sufficient.

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