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

With no annotations provided, the description carries the burden of behavioral disclosure. It does disclose the key outcome and the fact that the body is discarded. However, it does not mention redirects, timeouts, response shape, or how the many unrelated input parameters are treated, so the disclosure is only partially complete.

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?

Two short sentences, front-loaded with the result and ending with the most important behavioral caveat. Every word earns its place; there is no redundant or filler content.

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?

Despite a 9-parameter schema, no annotations, and no output schema, the description covers only the URL-focused behavior. It gives no guidance about the purpose of the extra inputs like city, feed, json, or path, so an agent cannot tell whether they are ignored, validated, or used as alternate fetch targets.

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. The description adds only the 'public URL' gloss and does not clarify how the nine optional parameters relate to fetching. The schema's url description ('normalize or cite') also conflicts slightly with the tool description's fetch behavior, leaving some ambiguity.

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 states a specific action and resource: return 'HTTP status and content type' for a 'public URL', with the key limitation 'Body discarded.' This is clear and useful, but it does not explicitly differentiate from sibling tools like fetch-status or normalize-url, so it stops short of full sibling distinction.

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 implies when to use the tool: when all you need is HTTP status and content type for a public URL and the body is not needed. It provides an implicit exclusion via 'Body discarded,' but it never names alternatives or explains when to prefer web-fetch over fetch-status, browser-url-ok, or normalize-url.

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