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

With no annotations, the description carries the behavioral disclosure burden. It meaningfully discloses that the body is discarded and the URL is expected to be public, but it does not mention redirects, error behavior, rate limits, or confirm the HTTP method used.

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, front-loading the core behavior and then stating the key limitation. There is no redundant or filler language.

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 core behavior is clear for a simple status/content-type check, but the return format is unspecified and the heterogeneous eight-parameter schema leaves ambiguity about which inputs are required or relevant. Without an output schema, the description is adequate but not fully complete for reliable invocation.

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?

The schema already provides descriptions for all eight parameters, so schema coverage is high and the baseline is 3. The description adds the body-discard behavior but does not clarify which parameters are actually relevant to the URL fetch or reconcile the url schema text ('normalize or cite') with the status/content-type behavior.

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 clearly states that the tool reports HTTP status and content type for a public URL, and adds that the body is discarded. It does not use an explicit verb like 'fetch' and does not differentiate itself from siblings such as fetch-status or browser-url-ok, so it is clear but not fully distinguished.

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 'HTTP status and content type for a public URL' implies the intended use case, and 'Body discarded' is a useful when-not signal that the response body is not available. However, it does not name alternatives or explicitly state when to choose this tool over similar sibling tools.

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