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

With no annotations provided, the description carries the behavioral disclosure burden. It adds one useful behavioral guarantee, 'Page content is not stored,' but it does not disclose whether a network request occurs, how redirects or failures are handled, or what the response structure looks like.

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 no filler. The primary behavior is front-loaded, and the storage note is meaningful safety context rather than 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?

A nine-parameter schema with no required fields and no output schema needs more explanation. The description never says whether the parameters are alternative modes, whether exactly one should be supplied, or what happens when url is absent. This leaves an agent guessing about the intended invocation pattern.

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 description does not need to repeat parameter meanings. It adds a little context by clarifying the expected output for the url parameter, but it contributes nothing to understanding the other eight parameters. The schema-based baseline of 3 applies.

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 is specific about the core behavior: 'Return host, scheme, and HTTP status for a URL.' This identifies a clear verb, output fields, and resource type. However, it does not acknowledge the other eight schema properties or explain how this differs from sibling tools like fetch-status or normalize-url.

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 about when to use this tool versus alternative URL-related siblings. 'Page content is not stored' hints that it is a lightweight, non-retentive option, but it never states when to prefer this over fetch-status, web-fetch, or normalize-url.

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