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

With no annotations, the description carries the behavioral burden. It does add a useful data-handling guarantee: 'Page content is not stored.' However, it does not state whether the URL is actually fetched, whether redirects are followed, or what side effects or errors may occur.

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 front-loaded sentence followed by a concise privacy note. Every sentence earns its place, and there is no redundant restatement of the tool name or schema.

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 for a 4-parameter tool with no annotations and no output schema. It does not explain the joint purpose of url, host, json, and zone, nor the expected return shape beyond three named fields. An agent selecting this tool would likely be confused about how to populate json or zone.

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 coverage is 100%, so the baseline is 3. The description does not add meaningful parameter semantics beyond what the schema already provides, and it especially does not clarify the roles of 'json' and 'zone', which seem unrelated to the URL-centric 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 clear action ('Return host, scheme, and HTTP status') and a specific resource ('for a URL'), which distinguishes it from most siblings. It is clear about what the tool does, though it does not explain how the 'citation' name relates to this behavior.

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 about when to use this tool versus alternatives such as normalize-url, inspect-robots, or status-catalog. The description offers no exclusions, prerequisites, or selection criteria; an agent is left to infer the appropriate context from the schema alone.

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