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

With no annotations, the description carries the behavioral burden. It clearly discloses that the response body is discarded, which is valuable and not visible from the schema alone. It does not mention redirects, timeouts, error behavior, or whether it only performs a GET request.

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?

A single, front-loaded sentence with no filler. Every clause adds meaning: the outcome, the URL scope, and the discarded body.

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?

The definition is enough for a simple status-and-content-type fetch, and the schema covers the parameters. But with no annotations, no output schema, and several similarly named sibling tools, the description is too sparse to fully disambiguate behavior around errors, redirects, and when the other input fields matter.

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 9 parameters in detail. The description adds only the general 'public URL' context and does not clarify which parameter is the primary fetch target or how the additional parameters interact with fetching.

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?

States a clear outcome: HTTP status and content type for a public URL, with the body discarded. This names the resource and the core return values, though it does not explicitly distinguish itself from the similar sibling fetch-status.

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 phrase 'for a public URL' gives a usage context and implies it is appropriate when only status and content type are needed, not full content. However, it does not explicitly state when to prefer this tool over siblings like fetch-status or browser-url-ok.

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