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

With no annotations, the description carries the full burden of behavioral disclosure. It does reveal that the body is discarded, which is useful, but it omits other important behaviors like redirect handling, timeout limits, authentication needs, or the exact response format. The sparse disclosure is insufficient for a network tool.

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 extremely concise at two sentences, with no wasted words. However, it is under-specified for a tool with nine parameters and no annotations, so the brevity is not 'appropriate' – it sacrifices necessary information for the sake of economy.

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?

For a complex tool with nine optional parameters, no output schema, and no annotations, the description is severely incomplete. It does not explain the return format beyond 'HTTP status and content type', nor does it clarify the purpose of the non-URL parameters, leaving agents without enough information to invoke the tool correctly.

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?

While schema coverage is 100% (baseline 3), the tool description adds no clarity about how the nine heterogeneous parameters relate to the stated purpose. Parameters like 'city', 'zone', and 'query' seem unrelated to fetching a URL, and the description does not explain their role or that only 'url' is relevant. The schema descriptions themselves are cryptic, and the tool description fails to compensate.

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 (fetch a public URL) and the specific outputs (HTTP status and content type), with a behavioral note that the body is discarded. However, it does not differentiate from sibling tools like fetch-status or browser-url-ok, which likely serve similar purposes, so it stops short of a 5.

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 provided on when to use this tool versus alternatives such as fetch-status, normalize-url, or browser-url-ok. There is no mention of prerequisites, exclusions, or selection criteria, leaving the agent to guess based on the name alone.

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