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

Annotations already cover read-only and non-destructive behavior. The description adds the valuable behavioral detail that no API key is required, which is not in the annotations. It also states the ranking criterion and shows the input format, providing context beyond the structured data.

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 very short, front-loaded with the core purpose, followed by a usage note and an example. Every sentence carries useful information; there is no filler or redundancy.

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 simple single-parameter read-only query tool, the description is complete: it states the purpose, ranking criterion, example input, and auth requirement. No output schema exists, and none is necessary for such a straightforward query. Annotations cover safety, and the example removes any ambiguity about invocation.

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?

The input schema already provides a full description of 'input' as a row limit, with the example passing 10. The description's example call repeats this information without adding new semantic meaning. With 100% schema coverage, baseline 3 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 clearly states the tool returns top ASNs ranked by announced-prefix count, with a specific verb and resource. It distinguishes itself from the sibling whisper_* tools, which have distinct names and purposes. The example call reinforces the 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?

The description provides a concrete example call, which implies usage, and notes that answers require no API key. However, it gives no explicit when-to-use or when-not-to-use guidance relative to sibling tools. Usage is mostly implied rather than stated.

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