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

With no annotations, the description carries the full burden of behavioral disclosure. It only states that no browser is launched, which is a useful behavioral trait, but it does not disclose whether the tool performs network requests, how errors are reported, or what side effects (if any) occur. The mismatch between the description's narrow focus and the 9 unrelated parameters also raises questions about undisclosed 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 extremely concise (two short sentences) but is under-specified for a tool with 9 parameters and no other documentation. It lacks structure, fails to mention parameters, and does not provide any context about input or output. Conciseness is not the issue; completeness is.

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 tool's complexity (9 optional parameters, no annotations, no output schema), the description is grossly inadequate. It only covers the core action and a single behavioral trait, leaving the agent without critical information about how to use the parameters, what the tool actually does with them, and what the result means. The description is far from sufficient for correct invocation.

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?

The schema covers all 9 parameters with descriptions, so the baseline is 3, but the tool description adds no value in explaining how these parameters relate to the stated purpose. The description implies a URL-focused tool, yet parameters like 'city', 'feed', 'json', and 'path' are unrelated and unexplained in the description, creating confusion rather than clarity.

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 the action (check whether a URL can be opened) and explicitly differentiates from sibling tools like playwright-url-ok by adding 'No browser is launched.' However, it does not specify what 'opened' means (e.g., HTTP status, DNS resolution, format validation), and the presence of many unrelated parameters in the schema suggests the description may not capture the full purpose.

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 description provides no guidance on when to use this tool versus alternatives such as fetch-status, normalize-url, or playwright-url-ok. It does not state conditions, prerequisites, or exclusions, leaving the agent to infer usage from the tool's name and the one-line description.

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