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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the description need not repeat those. It adds useful behavioral context: that data is 'right now' (current origin state) and that it returns aggregated counts rather than a list. It also mentions the cost, which is not covered by annotations. No contradictions with 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 tight and front-loaded: purpose first, then usage guidance, then cost. Every sentence adds value, and there is no redundant or promotional language. It fits in two sentences with no filler.

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 tool with one parameter, an output schema (which presumably documents the return fields like name, country, registry, contacts, and prefix counts), and clear sibling differentiation, the description is complete. It covers what the tool returns, when to use it, and its cost. Nothing essential is missing for an agent to invoke 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 fully documents the single 'asn' parameter with a description, examples, and type/range constraints. The description adds no additional parameter semantics beyond what the schema already conveys, so the baseline 3 applies for high schema coverage.

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 profiles an AS by returning registered organization details (name, country, registry, contacts) and current IPv4/IPv6 prefix counts. It also distinguishes itself from siblings by explicitly noting what it does not provide ('use pwhois_asn_prefixes for the prefix list, pwhois_asn_transit for prefixes it carries'), so the agent can select it correctly without ambiguity.

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 explicit usage direction: 'Use this for a quick profile' and then names the alternative tools and the conditions for choosing them. It also notes the query cost ('Costs 1 query'), which is relevant for quota management. This leaves no doubt about when to use this tool versus its siblings.

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