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

The description discloses that page content is not stored, which is a positive transparency note. However, it does not mention whether a network request is made, potential failures, or side effects beyond that. Without annotations, this is only partially transparent.

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 a single sentence, concise and to the point, with no unnecessary words. It fully conveys the core function in a compact form.

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 incomplete given the schema has 9 optional parameters and no required fields. It does not explain how parameters like 'city', 'feed', or 'zone' relate to the stated URL purpose, nor does it specify the output format. This creates ambiguity for an agent deciding to call the tool.

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 description does not add meaning beyond the schema's own parameter descriptions. Since schema coverage is 100%, the description provides no extra context for parameters like 'city' or 'ref', which are unrelated to the stated URL purpose.

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 action and resource: 'Return host, scheme, and HTTP status for a URL.' This is clear and distinguishes it from siblings like normalize-url or fetch-status, though it doesn't name them.

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?

It implies a use case (obtaining host/scheme/status without full content) but does not explicitly state when to use this over alternatives. The 'Page content is not stored' hint provides some guidance but lacks explicit comparisons.

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