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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the description does not need to cover safety. It adds useful context about the returned entities, but does not mention edge cases such as reserved/private IPs or missing data behavior.

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 one short, information-dense sentence. It front-loads the verb and resource, lists the outputs, and contains no filler or redundant repetition of the title.

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 single-parameter read-only lookup tool, this is complete: the input is defined by the schema, the output scope is stated, and annotations cover the operational semantics. No additional context is necessary for correct 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?

Schema coverage is 100% and the ip parameter already includes a description ('IPv4 or IPv6 address'). The tool description does not add novel parameter information beyond what the schema provides, so the baseline of 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 uses a specific verb ('Resolve') with a clear input (IP) and names three concrete outputs: autonomous system number, organization, and network prefix. This distinguishes it from siblings like geo_ip or geo_enrich that focus on location or general enrichment.

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 intended use is implied by the ASN-specific output, but the description does not explicitly state when to choose this over related tools such as geo_ip or geo_enrich. It lacks an explicit alternative or exclusion, so a caller must infer the routing from the tool's scope.

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