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

The description does disclose that the body is discarded and some schema descriptions note that values are discarded after checks. However, it does not explain network behavior, redirect handling, error cases, response size limits, or how the many schema parameters interact with the actual fetch.

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 main tool description is concise and direct. The schema is padded with many one-off fields and repetitive 'discarded' language, which adds noise, but the core prose itself is economical.

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 network-fetching tool, the description omits important operational details such as the return format beyond 'status and content type', error behavior, redirect handling, and whether any of the other schema fields affect the fetch. Without this context, an agent may not know how to handle failures or edge cases.

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?

Every parameter has a description, but the descriptions are often unrelated to the stated purpose of the tool. For example, 'url' is described as 'HTTPS URL to normalize or cite' rather than a URL to fetch, while fields like 'ref', 'city', and 'query' are described only as discarded after checks.

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 headline sentence clearly states that the tool returns HTTP status and content type for a public URL while discarding the body. However, the input schema lists nine unrelated optional parameters with confusing descriptions, which muddies what the tool actually operates on and what is ignored.

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 use this tool versus sibling tools such as fetch-status, normalize-url, or browser-url-ok. There is no mention of redirects, timeouts, authentication, or when the other schema fields would be relevant.

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