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 only that no browser is launched, but does not describe what the check actually does (e.g., HTTP status, syntax validation, side effects, or permissions). This is insufficient for an agent to predict behavior.

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 short (two sentences) but under-specified. It is not a case of effective conciseness; it omits critical details and offers no structure to guide an agent. The 'No browser' note is useful but insufficient.

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?

For a tool with nine parameters, no annotations, and no output schema, the description is completely inadequate. It fails to explain the tool's actual behavior, return value, or usage context, leaving an agent unable to invoke it 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?

Schema description coverage is 100%, so the baseline is 3. However, the tool description does not explain how the nine parameters—many unrelated to URLs (city, json, zone, query)—relate to the stated purpose of checking a URL. This mismatch can confuse an agent about which parameter to supply for a given task.

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 verb ('Check') and a resource ('whether a URL can be opened'), but the term 'opened' is ambiguous—does it mean HTTP reachability, syntactic validity, or DNS resolution? It also does not distinguish from siblings like browser-url-ok or normalize-url beyond the 'no browser' note.

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 guidance on when to use this tool versus alternatives. The only hint is 'No browser is launched,' which implies a lightweight check but does not explicitly route an agent to a sibling for cases requiring browser rendering or URL normalization.

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