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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so safety and external-dependency behavior are covered. The description adds value the annotations don't: it enumerates the result categories and states the fallback behavior when 'ip' is omitted, which is meaningful for an external-intelligence lookup. It does not mention rate limits, caching, or per-provider variance, keeping it below a 5.

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?

Two sentences, front-loaded with the primary capability and followed by the conditional default. Every clause carries information (return domains, supported address families, omission behavior) 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?

With no output schema, the description correctly shoulders the burden of describing the return payload by naming each data category, and it explains the zero-argument default. It is nearly complete for a single-optional-parameter read tool; only failure modes (invalid address, unsupported input) are left unaddressed.

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?

There is only one optional parameter and schema description coverage is 100%, so the schema already documents both the address format and the omit-to-self behavior. The description restates the same IPv4/IPv6 and omission semantics without adding syntax, format, or validation detail beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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 ('Retrieve') with a clearly identified resource (an IPv4/IPv6 address) and enumerates the data categories returned: geolocation, ASN/ISP, and proxy/VPN/Tor/threat intel. This is far more specific than the tool name alone and cannot be confused with the unrelated siblings (get_balance, search_nearby_poi, validate_email).

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?

Usage context is unambiguous: call this to inspect an address, and omit 'ip' to inspect yourself. There are no exclusions or named alternatives, but the sibling tools occupy entirely different domains, so no routing guidance is genuinely needed. The one gap is that it doesn't state when the tool would be inappropriate (e.g., hostnames or CIDR ranges).

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