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

The description discloses a real behavioral trait: it returns only the HTTP status and discards the body. However, with no annotations present, it does not cover expected network behavior such as redirects, timeouts, or error handling, and it never explains why nine unrelated optional parameters are accepted.

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 with no filler: the first states the core purpose and the second states the key behavioral constraint. Every word earns its place and the information is front-loaded.

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?

With nine optional parameters and no output schema or annotations, this two-sentence description is insufficient. It does not say which parameter identifies the URL to check, what the returned status looks like, or what happens when multiple parameters are provided.

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 applies; the schema already documents each parameter. The main description adds only the 'public library docs URL' framing, but does not map it to the `url` parameter, and the schema's `url` description ('normalize or cite') sits awkwardly with the HTTP-status purpose.

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 specific operation ('HTTP status') and a specific resource ('public library docs URL'), and the added note 'Body discarded' clarifies scope. It does not explicitly contrast with siblings such as fetch-status or browser-url-ok, so it stops short of full sibling differentiation.

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 about when to use this tool versus the many URL/status siblings (fetch-status, browser-url-ok, normalize-url). No alternative conditions or exclusions are provided, so the agent must infer fit from the name alone.

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