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

With no annotations, the description carries the burden of behavioral disclosure. It usefully discloses that the body is discarded and that the URL must be public. However, it omits other behavioral details an agent may need, such as request method, redirect handling, timeouts, or the exact output/return contract.

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 compact sentences with no filler, and the primary behavior is front-loaded. It is efficient and readable, though brevity comes at the cost of omitting important schema and sibling-tool guidance.

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 tool has 9 optional parameters, no annotations, and no output schema, yet the description addresses only the URL case. It does not explain how the other accepted inputs behave, what happens if multiple fields are provided, or what the response will look like, leaving the description incomplete for real invocation decisions.

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 documents all 9 parameters with 100% coverage, so the baseline is 3. The description adds little beyond the 'public URL' qualifier and does not clarify the relationship between the URL-only description and the many non-URL schema fields like city, iana, query, and json.

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 the tool returns HTTP status and content type for a public URL and explicitly notes the body is discarded. This gives a specific verb-like capability and a clear resource. However, it does not distinguish this tool from similar siblings such as fetch-status or browser-url-ok, so it stops short of a 5.

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 implies a lightweight status/content-type use case and warns the body is not returned, which is a useful exclusion. But it never names alternative tools, states when to prefer them, or explains which of the nine schema inputs should be used in which situation.

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