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

With no annotations, the description must carry the full behavioral burden. It discloses that the body is discarded but says nothing about how the many other parameters are handled or whether the operation is read-only. The mismatch between the description's narrow focus on URLs and the schema's broad parameter set creates ambiguity.

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 sentence, front-loaded with the core action, and contains no filler. It earns a high score for efficiency, though it sacrifices completeness for brevity.

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 tool has nine parameters, no output schema, and no annotations, yet the description only addresses the URL case. It fails to explain the role of the other parameters or the tool's behavior in non-URL scenarios, leaving the agent without sufficient context to use it 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?

Schema coverage is 100%, so the baseline is 3. The description adds no extra meaning beyond the schema for any parameter, including 'url', and does not clarify the purpose of the other eight parameters. It neither enriches nor contradicts the schema, so a baseline score is appropriate.

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 verb ('fetch') and resource ('public URL'), and notes the body is discarded, which is a useful differentiator. However, the tool's schema includes nine unrelated parameters (city, zone, query, etc.) that are not mentioned, making the stated purpose misleading about the tool's actual scope.

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?

The description gives no guidance on when to use this tool versus siblings like fetch-status or browser-url-ok. There is no mention of alternatives, exclusions, or preferred contexts, leaving the agent to infer usage from the name alone.

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