ASN Lookup

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

Beyond annotations (readOnly, idempotent, non-destructive), the description discloses default truncation (first 50 prefixes), the effect of setting include_full_prefixes=True, and that ipv4_count and ipv6_count are honest pre-truncation totals. It also includes rate limits. 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 succinct (three sentences) with the main purpose front-loaded. Every sentence adds useful information, and there is no redundant or extraneous content.

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 description covers inputs, outputs (with a clear return format hint), and default behavior. Given the presence of an output schema, the description is sufficiently complete. It does not cover error cases, but the tool is simple enough.

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?

Both parameters have schema descriptions (100% coverage). The description adds value by explaining the default behavior for include_full_prefixes and providing a concrete example (Cloudflare AS13335) to illustrate when to use it.

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 looks up ASN for a domain or IP, specifying what it returns (AS number, organization, IPv4/IPv6 prefixes). It distinguishes from sibling lookup tools by focusing on network operator identification.

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 context on when to use the tool (e.g., for network mapping or BGP route audits) and mentions default vs. full prefix behavior. It does not explicitly mention when not to use it or list alternatives, but the context is clear enough.

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