calculate_age

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

No annotations are provided, so the description carries the full burden. It explains the computation (years, months, days) and the optional 'as_of' parameter defaulting to today. No side effects or destructive behavior is relevant, and the description is 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?

The description is concise with two sentences and a bullet list of parameters. It front-loads the purpose and efficiently conveys all necessary information without waste.

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 the tool's simplicity and the presence of an output schema (not shown), the description covers the core functionality. It could include a brief example or note about return format, but it is still adequate 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 description coverage is 0%, but the description adds essential meaning: birthdate is required and in ISO format, as_of is optional with default today. This goes beyond the schema's type and title, providing clear usage guidance.

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 'Calculate precise age from a birthdate' with a specific verb and resource. It distinguishes itself from sibling tools like 'calculate_bmi' or 'calculate_date' by focusing on age computation in years, months, and days.

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 explicitly says 'Use this to compute someone's age...' and provides context for when to use it. It does not explicitly state when not to use or name alternatives, but the purpose is clear enough given the tool's specific function.

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