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 explicitly states that page content is not stored, which is useful, but it does not disclose side effects for the other parameters (e.g., whether they trigger network calls), authentication needs, or error behaviors. The single disclosure is too minimal.

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, tightly written sentence that front-loads the primary purpose. No filler words. It earns a high conciseness score, though the under-specification of the multi-parameter scope slightly reduces structure effectiveness.

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 nine parameters, no output schema, and no annotations, the description is far from complete. It only addresses the URL case and leaves the purpose and behavior of the other eight parameters unexplained. An agent cannot know how to properly invoke the tool for non-URL inputs, making the description inadequate for the tool's actual complexity.

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 each parameter has a one-line explanation. However, the tool description itself does not add meaningful context beyond the schema; it only explains the URL-related output while ignoring the other eight parameters. The schema descriptions are quirky (e.g., 'discarded after the shape check') but do convey some intent, so the description doesn't need to repeat them. Baseline 3 is appropriate.

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 a specific verb ('Return') and resource ('host, scheme, and HTTP status for a URL'). However, it does not differentiate from sibling tools like fetch-status or normalize-url, and the presence of nine parameters with unrelated names (city, feed, json, etc.) makes the overall purpose ambiguous. It isn't a tautology, but it's not fully clear about the full scope.

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?

No guidance is provided on when to use this tool versus alternatives. The description only states what it returns, not the context or conditions for selection. Since many siblings could perform similar URL checks, the omission is significant.

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