get_domain_age

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

With no annotations, the description carries the behavioral transparency burden. It discloses the RDAP mechanism, that it only works for taken/registered domains, and the 'could not determine' edge case for ccTLDs like .co. It could provide more detail on exact output formatting, but it is adequately transparent.

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?

Three sentences, all information-dense: the core action, the use case, the sibling distinction, and the edge-case limitation. No filler or redundant 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?

This is a simple one-parameter tool with complete schema coverage and no output schema. The description covers purpose, applicability, limitation, and sibling differentiation, making it complete for an agent to select and invoke 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?

Schema coverage is 100%, so baseline is 3. The schema already describes the domain parameter as fully-qualified and meaningful only for taken domains; the description reinforces this but adds little semantic detail beyond what the schema provides.

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?

Description opens with a specific verb+resource: 'Return the registration (creation) year and expiration date of a TAKEN domain, via RDAP.' It clearly states what the tool does and explicitly distinguishes it from check_domain by noting it does NOT report availability.

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?

Explicitly states when to use the tool: 'Use to gauge how long a name has been held or when it may expire.' It also names the alternative for availability checks: 'use check_domain for that.' The scope (taken domains only) is clearly stated.

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