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

The description discloses that the response body is discarded, which is a key behavior. However, it does not mention potential side effects, error handling, redirect behavior, or rate limits. Since no annotations are provided, the description carries the full burden but leaves gaps.

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, using only two sentences. It manages to convey the core operation and a key behavior without unnecessary details, making it easy to parse and understand.

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 has 9 parameters and no output schema, the description is too brief. It does not explain the return format beyond 'HTTP status and content type', nor does it cover error scenarios, the purpose of the extra parameters, or any usage caveats. This leaves an agent with significant ambiguity about how to effectively invoke the tool.

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?

Although all 9 parameters have descriptions in the schema, the tool's stated purpose (fetching a URL) aligns only with the 'url' parameter. The other parameters (city, feed, json, query, etc.) seem unrelated to web fetching, and the tool description does not clarify why they are present or how they are used, causing confusion.

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's function: retrieving HTTP status and content type for a public URL while discarding the body. It uses a specific verb (fetches) and resource (public URL), though it does not explicitly contrast with sibling tools like fetch-status or browser-url-ok.

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 numerous URL-related alternatives (e.g., fetch-status, normalize-url, playwright-url-ok). The note 'Body discarded' hints at a use case, but there is no explicit recommendation or condition.

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