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

With no annotations, the description carries the full burden. 'Body discarded' is a useful behavioral disclosure beyond the schema. However, it omits other relevant behavior such as redirect handling, error behavior, rate limits, or whether any content is persisted or processed.

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, no filler, with the most important operational detail ('Body discarded') front-loaded. The description is appropriately concise for what it does say.

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 too thin for a tool with 9 optional parameters, no required fields, and no output schema. An agent cannot tell whether city, feed, json, path, zone, query, and ref are alternative modes, ignored fields, or inputs to a broader polymorphic operation. This is a significant gap in call correctness.

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 adds minimal parameter-level meaning: it identifies 'url' as the primary input via 'public URL'. It does not explain the relationship between the many other accepted parameters and the stated URL-fetching 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 clearly states the tool returns HTTP status and content type for a public URL, and adds the important clarification that the body is discarded. However, it does not differentiate it from the sibling tool 'fetch-status', which appears to serve a very similar purpose.

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 versus alternatives like fetch-status, browser-url-ok, or normalize-url. The phrase 'public URL' implies a scope constraint, but there are no explicit when-to-use or when-not-to-use instructions.

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