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

Beyond the annotations (readOnly, openWorld, idempotent), the description discloses that large networks are truncated at 2,000 rows per family and that each family costs one query. These are important behavioral traits not covered by annotations.

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 two efficient sentences that front-load the core purpose and immediately follow with usage alternatives and constraints. Every sentence earns its place; there is no filler or repetition.

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?

Given the output schema exists, the description covers the tool's purpose, parameter semantics, usage distinctions, truncation behavior, and query cost. An agent has everything needed to decide when and how to call 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?

The schema covers asn with a clear description and examples, while the family parameter lacks a schema description. The tool description compensates by explaining 'family: v4, v6 or both (default both)', fully clarifying the enum and default. This adds value beyond the structured schema.

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 every prefix announced with the given AS as origin, including AS path and first-seen time. It distinguishes itself from siblings by explicitly naming the transit and count alternatives, so an agent can immediately tell what it does and what it is not.

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?

It gives explicit routing guidance: use pwhois_asn_transit for transit prefixes and pwhois_asn_info for counts without the list. It also states the default family behavior and truncation limit, so an agent knows exactly when to invoke this tool versus alternatives.

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