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

There are no annotations to rely on, so the description carries the burden. It does disclose one useful behavioral fact ('Page content is not stored'), but it omits other important behaviors: that most of the parameters are explicitly discarded, how URL lookup or status checking behaves, and whether the tool has side effects beyond the lookup.

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 sentences with no filler; the primary behavior is front-loaded and the storage-disclosure sentence earns its place. It is appropriately sized for the amount of signal it provides, even though other aspects of the tool definition are sparse.

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?

Given the tool's overloaded schema with eight parameters, a large sibling group of URL and status tools, and no output schema, the description is not complete enough for confident invocation. It never states which parameter is the required input, what the return shape looks like, or how this tool relates to the many nearby siblings.

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 input schema already provides descriptions for all parameters, including explicit discard notes, so the description does not need to repeat them. The description adds only a top-level focus on 'a URL', which helps connect the schema's many parameters to the intended use but does not meaningfully extend the per-parameter explanations.

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 output ('host, scheme, and HTTP status') and the target resource ('a URL'), which gives an agent a concrete model of what the tool does. However, it does not differentiate itself from sibling tools like fetch-status or normalize-url that could plausibly return similar information, and the tool name 'citation' is not self-explanatory.

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?

No guidance is given about when to use this tool instead of alternatives such as web-fetch, fetch-status, or normalize-url. The note that 'Page content is not stored' hints at a privacy-related use case, but there is no explicit when-to-use or when-not-to-use guidance.

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