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

With no annotations, the description carries the full burden of behavioral disclosure. It does reveal the HTTP method and the limited return value, which is useful, but it does not explain behavior for the other eight parameters, possible side effects, error handling, or why several parameters are described as 'discarded' in the schema.

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, front-loaded sentence with no redundancy. It states the action and the limited return value efficiently, and every word earns its place.

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 nine optional parameters, no annotations, and no output schema, a one-line description is insufficient. The agent is left uncertain about which parameter to use, whether other parameters are alternatives or ignored, what the exact response shape is, and how this tool fits among the many 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 every parameter is already documented in the schema. The description adds only the 'public URL' framing and 'status only' return scope, not meaningful parameter-level semantics beyond what the schema provides, so the baseline of 3 applies.

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 a specific action ('HEAD a public URL') and return scope ('status only'), and this distinguishes it from content-fetching siblings like web-fetch or browser-url-ok. However, it does not account for the many non-URL parameters in the schema, so the stated purpose is clear but incomplete relative to the tool's apparent surface.

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 given about when to prefer fetch-status over related siblings such as normalize-url, browser-url-ok, or web-fetch, nor are exclusions or conditions stated. The phrase 'status only' implies a lightweight alternative to fetching full content, but that is left to inference rather than made explicit.

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