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

With no annotations, the description carries the behavioral disclosure burden. It openly states that page content is not stored, which is a meaningful disclosure, and it clearly limits the return to host, scheme, and HTTP status. However, it leaves out important behaviors such as whether the URL is fetched over the network, redirect handling, timeouts, or any potential side effects.

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 short sentences with no wasted words. The primary action is front-loaded, and the 'not stored' caveat is a useful, relevant follow-up. Every clause 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?

Despite complete schema coverage, the tool remains under-specified for an agent. The optional parameters json and zone appear unrelated to the stated purpose of returning URL metadata, and no output schema is provided. An agent would be unsure whether to supply these parameters or what the exact response shape is.

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. The description adds context by naming host, scheme, and HTTP status as the operation's output, but it does not clarify how the host, json, and zone parameters fit into the citation process. It neither contradicts nor significantly enhances 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 states a specific operation: return host, scheme, and HTTP status for a URL. The phrase 'Page content is not stored' further separates this from tools that fetch or store content. It doesn't explicitly name sibling tools, but the core purpose is clear and unambiguous.

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 on when to use this tool versus alternatives. It does not reference sibling tools like normalize-url or validate-json, nor does it state conditions like 'use this to cite a URL, not to validate JSON.' The 'not stored' line hints at scope but does not provide actionable usage context.

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