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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does reveal one useful trait—'Body discarded'—but it omits essential behavior such as what happens when multiple parameters are supplied, which parameters trigger a check, what the HTTP status is for, and whether any input is actually fetched or merely shape-checked.

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 only two short sentences with no filler. 'HTTP status for a public library docs URL' is front-loaded and 'Body discarded' adds a useful behavioral detail without waste. As a piece of writing it is extremely concise and well structured.

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 output schema, no annotations, and a large sibling list, one sentence is nowhere near enough. An agent cannot tell which parameter to supply, whether the parameters are alternatives or complements, what the response actually contains, or how this tool relates to similar URL/status tools. The definition is critically incomplete.

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 schema already documents all nine parameters. The description adds no parameter-level meaning beyond singling out `url`, which is insufficient for the other eight parameters, but the full schema coverage keeps this at baseline rather than lower.

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 names a clear verb and resource: return an HTTP status for a public library docs URL and discard the body. However, it only accounts for the `url` parameter while the schema exposes eight other parameters (`city`, `feed`, `json`, `zone`, etc.), so the stated purpose is narrower than the actual tool surface. It also does not distinguish the tool from siblings like `fetch-status`, `browser-url-ok`, or `normalize-url`.

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?

There is no guidance on when to use this tool versus its many siblings, and no mention of alternatives or exclusions. The implied narrow use case (public library docs URL) is misleading given the schema accepts a wide variety of unrelated inputs, so the description actively misleads rather than helps.

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