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

With no annotations present, the description carries the behavioral disclosure burden. It responsibly discloses that the body is discarded and that the result is limited to HTTP status and content type, which prevents an agent from expecting response body content. It does not cover redirects, timeouts, or error behavior, but those are less critical for a simple fetch tool.

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 two short sentences with no filler. Every word earns its place: 'HTTP status and content type' defines the output, 'public URL' scopes the input, and 'Body discarded' is a critical behavioral note.

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?

Despite a 9-parameter schema and no output schema, the description only addresses a single URL use case and gives no guidance on how to choose among the many optional parameters. It also does not specify the return format in enough detail or contrast with the similarly named fetch-status sibling. An agent would likely hesitate about which parameters to supply.

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?

All nine parameters already have detailed descriptions in the input schema, so the baseline is 3. The tool description adds no parameter-level guidance and does not clarify how 'url' relates to the other eight optional fields, some of which look unrelated to fetching. It neither contradicts the schema nor meaningfully enhances it.

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 what the tool produces: HTTP status and content type for a public URL, and explicitly says the body is discarded. It is specific enough to distinguish from unrelated sibling tools like normalize-url or validate-json, though it does not explicitly differentiate itself from the closely named fetch-status sibling.

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 gives no explicit guidance about when to use this tool versus alternatives. It does not mention fetch-status, browser-url-ok, playwright-url-ok, or any other sibling, nor does it provide exclusions or preferred conditions. The only usage context is weakly implied by 'public URL.'

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