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

With no annotations provided, the description carries the full burden. It does disclose one important behavior: the body is discarded, so callers cannot expect content back. It also limits usage to public URLs, implying no auth or private access, but it omits network side effects, redirect handling, timeout behavior, and error semantics.

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 two short sentences with no filler. The core purpose is front-loaded and the body-discarded note is a valuable, compact behavioral addition.

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?

For a tool with nine optional parameters, no annotations, and no output schema, this description is too thin. It covers one URL-based use but leaves the large optional parameter surface unexplained, does not describe the return structure beyond two fields, and omits failure modes and relationship to similarly named sibling tools.

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, but the description adds nothing about parameters and the schema itself is mismatched: url is described as 'HTTPS URL to normalize or cite' rather than fetching status/content type, and the other eight parameters (ref, city, json, path, zone, query, feed, host) have no clear connection to the described tool behavior. This undermines parameter selection.

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 identifies the resource (a public URL) and the outputs (HTTP status and content type), and explicitly notes the body is discarded. It is distinguishable from normalizing or validating tools like normalize-url or validate-json, though it does not explicitly contrast with the similarly named fetch-status sibling.

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 phrase 'public URL' gives a scope condition, and 'Body discarded' implies the tool should not be used when the response body is needed. However, it does not name alternatives such as fetch-status, browser-url-ok, or inspect-robots, nor does it state when to prefer one over another.

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