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

With no annotations, the description carries the behavioral burden, and it does disclose the key behavior: only HTTP status and content type are returned, and the body is discarded. However, it does not clarify how the many other schema parameters are handled, nor what happens on redirects, errors, or non-public URLs.

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 concise and front-loaded: the core purpose is stated in the first sentence, and the body-discard caveat is in the second. It has no filler, though it could have used an extra sentence to reconcile the multi-parameter schema.

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 parameters, no output schema, and no annotations, this description is too thin. It does not explain which parameter to pass for which use case, what the return format looks like, or how it relates to the many sibling fetch/validation tools.

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%, and every parameter already has an explicit description, so the tool description does not need to repeat them. Still, the description adds no guidance on choosing among the 9 parameters, leaving the schema to do all the work.

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 states a specific verb and resource: it returns HTTP status and content type for a public URL, and notes that the body is discarded. This is clear at a high level, but it ignores the 8 other parameters in the schema, so the actual input scope is underrepresentated.

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?

There is no explicit guidance on when to use this tool versus siblings like fetch-status, browser-url-ok, or normalize-url. The phrase 'Body discarded' implies a lightweight status check, but no alternatives or selection conditions are named.

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