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

The description mentions 'Body discarded' which is a behavioral detail, but it does not disclose potential errors, timeouts, or side effects. Since no annotations are provided, the description carries the burden, and it only partially fulfills this.

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 concise sentence, with no redundancy or unnecessary detail. It is well-structured and easy to parse.

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?

The description omits the broader context of the tool, especially the purpose of the numerous non-URL parameters. It fails to provide a complete picture, leaving the agent unsure how to interpret the schema.

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 description focuses solely on a 'public URL', yet the schema includes many unrelated parameters (e.g., ref, city, feed, json, path, zone, query). This mismatch means the description does not meaningfully explain the purpose of these parameters, despite each having its own schema description.

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 tool fetches HTTP status and content type for a public URL, with the body discarded. This is specific and unambiguous, making the primary purpose easy to grasp.

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 the many siblings like fetch-status, normalize-url, or browser-url-ok. The description lacks any indication of appropriate use cases or conditions.

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