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

With no annotations, the description must carry the behavioral disclosure burden. It does add one useful transparency statement, 'Page content is not stored,' which addresses retention. However, it does not mention network-fetch behavior, auth requirements, rate limits, or how the many other input params are handled beyond what the schema says.

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 short sentences with no filler. The core behavior is front-loaded, and the privacy-relevant note is kept separate and minimal. Every word earns its place.

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 explains the main return value and one behavioral guarantee, which is enough for the simple URL-facing case. However, the tool has nine optional parameters, no annotations, and no output schema, so an agent could be uncertain whether non-URL parameters affect behavior. The schema fills much of the gap, but the overall context is not fully complete.

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 is 3 even without parameter details in the description. The phrase 'for a URL' does help identify the url parameter as the operative one, but the description adds no additional parameter semantics beyond the schema.

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 a specific action and resource: 'Return host, scheme, and HTTP status for a URL.' It is unambiguous about what the tool computes, though it does not distinguish itself from siblings like fetch-status or normalize-url, and the tool name 'citation' is not directly explained.

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 guidance on when to use this tool versus alternatives, nor any mention of which parameter is the intended primary input. The description simply states what the tool returns, leaving tool selection and invocation strategy entirely to the agent.

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