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

With no annotations, the description carries the full burden. It discloses that the body is discarded, which is a useful behavioral detail, and implies read-only access by stating 'public URL'. However, it does not mention error behavior, rate limits, or what happens with non-URL parameters, leaving gaps for an agent to discover.

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 that efficiently conveys the primary function and a key limitation. It wastes no words and places the core action first. This is an exemplary level of conciseness.

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 the 100% schema coverage, the tool has 9 parameters and no output schema, and the description is too narrow to cover its actual behavior. The description mentions only 'HTTP status and content type' but the parameters include city, zone, json, path, etc., which are not URLs. This mismatch leaves an agent unsure about the full scope and return format. The description should clarify that these parameters are discarded or that the tool serves multiple purposes.

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 schema already documents all 9 parameters. The description adds no additional meaning about how parameters relate to the tool's purpose, nor does it clarify that many parameters (like city, zone, json) seem unrelated to the stated 'public URL' function. Baseline 3 applies since the schema does the heavy lifting.

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 verb (fetch) and resource (public URL), and specifies the outcome (HTTP status and content type). It is specific enough to understand the core function, but it does not explicitly differentiate from sibling tools like fetch-status or normalize-url, so it loses a point.

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. It does not mention scenarios where this tool is preferred over fetch-status, browser-url-ok, or normalize-url, nor does it state any exclusions. The only implicit hint is the emphasis on 'public URL' and discarding the body, but no explicit routing is provided.

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