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

No annotations are present, so the description carries the full burden. 'Body discarded' is a useful behavioral hint, but it does not disclose network behavior, redirects, timeouts, error handling, side effects, or whether this is a safe read-only operation, leaving the agent underinformed.

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 primary action and a key behavioral note are front-loaded. 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?

For a tool with 9 optional parameters, no annotations, no output schema, and many close siblings, this description is not complete enough to invoke correctly. It does not say which parameter(s) to use, what the status response looks like, or how to handle the unrelated schema properties.

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; each parameter already has an individual description. The tool description adds no parameter-level meaning and even conflicts with the `url` property's 'normalize or cite' purpose, but the schema itself is self-documenting.

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 concrete output ('HTTP status') and a specific resource ('public library docs URL'), so it is more than a tautology. But the input schema exposes nine unrelated optional parameters (city, feed, json, zone, query, etc.), and the `url` parameter is described as 'normalize or cite' rather than a docs URL, making the stated purpose misleading. It also does not distinguish this from overlapping siblings such as fetch-status or browser-url-ok.

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 a use case for checking a public library docs URL, but it gives no when-to-use or when-not-to-use guidance. With numerous sibling URL/status tools (fetch-status, browser-url-ok, playwright-url-ok), an agent has no basis for choosing this one over them.

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