age_calculator

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

With no annotations, the description carries the transparency burden. It discloses the input format (YYYY-MM-DD) and the return value (years plus exact days), but does not mention behavior for invalid dates, future birth dates, leap years, or the exact return structure. This is adequate for a simple calculator but not comprehensive.

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 three short sentences that front-load the purpose, then provide input format and output details. There is no fluff; every sentence earns its place.

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 states the return value as 'age in years + exact days' but does not clarify the precise shape (e.g., separate fields, string, object). It also omits edge-case handling. This is moderately complete for a single-param tool but leaves some details to the agent's inference.

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%, so the description must compensate for the bare birthDate string parameter. It adds crucial semantics by specifying the format (YYYY-MM-DD) and its purpose in the tool. This is meaningful addition 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 clearly states the tool computes age from a birth date and specifies the output as years plus exact days. It is distinct from the generic converters and date_difference_calculator, though it does not explicitly name alternatives or contrast with them.

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 is implied by 'Age from birth date' – an agent can infer it is for age calculation. However, there is no explicit guidance about when to choose this tool over the similar date_difference_calculator or any exclusions, leaving some ambiguity.

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