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 does disclose that 'No browser is launched', which is useful, but it omits any details about side effects, what 'opened' means, or why parameters like 'ref' and 'city' are accepted and discarded. The behavior for non-URL inputs is completely undisclosed.

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 sentence, so it is concise, but it is under-specified. It provides no structure or hierarchy, and the brevity comes at the cost of essential context. It is not verbose, but it is too short to be useful.

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 the complexity (9 parameters, no annotations, no output schema), the description is grossly inadequate. It fails to explain the full scope of the tool, the purpose of the many parameters, the meaning of 'discarded after the check', or any usage context. An agent cannot correctly call this tool based on the current definition.

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 baseline is 3, but the description adds zero clarification about how parameters relate to the tool's purpose. The presence of many unrelated parameters without explanation in the description makes it impossible for an agent to know which parameters are relevant or what the tool actually does with them. The description fails to compensate for the apparent mismatch between name and schema.

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 specific verb ('Check') and resource ('URL'), but the input schema exposes 9 parameters (ref, city, feed, host, json, path, zone, query) that are unrelated to URL checking, and several are described as 'discarded after the check'. This suggests the tool actually performs a broad shape-check across many input types, yet the description only mentions URLs, making the purpose ambiguous and potentially misleading.

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 alternatives like normalize-url, fetch-status, or playwright-url-ok. No mention of exclusions, prerequisites, or selection criteria. The agent is left to infer usage solely from the name and narrow description.

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