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

With no annotations provided, the description carries the transparency burden. It explicitly discloses that page content is not stored, which is a meaningful privacy and side-effect guarantee. It does not cover error behavior or redirects, but the disclosure goes beyond a bare purpose statement.

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?

Two sentences, with the output front-loaded in the first and a key caveat in the second. There is no redundant wording.

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 description is adequate for a simple URL checker, but it is not fully complete given the multi-parameter schema and lack of output schema or annotations. It does not explain how the other parameters relate to the described behavior or what happens on invalid URLs, so an agent must infer some behavior from the schema.

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 baseline applies. The description adds that the tool operates on a URL, matching the 'url' parameter, but it does not clarify the role of the six other parameters such as city, feed, json, and path, which is confusing given the narrow description.

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 ('Return'), resource ('URL'), and output tuple ('host, scheme, and HTTP status'). It is clear, but it does not explicitly differentiate itself from sibling tools such as fetch-status or normalize-url, which overlap in output scope.

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 only usage hint is 'Page content is not stored,' which implies this tool is for metadata rather than content retrieval. However, it never names alternative tools like web-fetch or states when to prefer this tool over them, leaving the routing to inference.

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