age_calc

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does disclose return values (next birthday, days until, zodiac, generation, weekday, leap-year info), which is useful, but it does not explain how timezone or reference date affect results, nor does it specify edge cases (e.g., invalid dates, leap year handling specifics) or output format.

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 a single sentence that efficiently conveys the core purpose and enumerates the calculated outputs. Every piece of information adds value, with no filler or redundancy. The structure is front-loaded with the primary function.

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 has 3 parameters, no annotations, and no output schema, the description should compensate by explaining parameter formats, timezone handling, and return structure. It does not. Key details like date format, timezone effect, and reference date behavior are missing, leaving critical gaps 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 only 33%, with only 'reference' having a description. The description does not explain the meaning or format of 'date_of_birth' or 'timezone', nor does it clarify default values beyond the schema's default for timezone. The description mentions 'date of birth' but not how the parameter should be structured, leaving agents to guess the date format.

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 verb 'Compute' and the resource 'age in years/months/days from a date of birth', which distinguishes it from sibling tools like date_math or timestamp. It also lists specific outputs (zodiac, generation, etc.), making the tool's purpose unambiguous.

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 implies usage for age calculation from a birth date but does not explicitly state when to use this over alternatives like date_math, nor does it provide any exclusions or conditions. There is no mention of compatibility with other tools, leaving the usage guidance implicit.

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