asn_lookup

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

With no annotations, the description fully discloses behavior: it is read-only, requires no API key, and is rate-limited. It lists the return fields but does not mention error handling (e.g., if query is invalid or not found), which would improve transparency.

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 concise and well-structured: purpose first, then usage guidance, then constraints and return fields. No redundant or unnecessary information.

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 there is no output schema, the description sufficiently lists the return fields (operator, prefixes, classification, abuse contact) and constraints (read-only, rate-limited, no API key). It covers all essential context for a simple lookup tool with good sibling differentiation.

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% and the single parameter 'query' is already well-described in the schema. The description restates the same information (IP address or AS number format) without adding new semantic meaning beyond the 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 uses the specific verb 'Look up' and clearly identifies the resource (Autonomous System / BGP information) and the returned data (operator, prefixes, classification, abuse contact). It explicitly distinguishes from the sibling 'reverse_dns' by stating when to use that instead.

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 explicit context for when to use the tool ('identify who runs a network or whether an IP is cloud/CDN-hosted') and when not to (use reverse_dns for host-level PTR). It also notes that it is read-only, requires no API key, and is rate-limited.

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