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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, which fully describes a pure-computation tool. The description adds nothing beyond that (no output shape, no format handling, no timezone/leap-year notes), so it neither contradicts nor enriches the structured data.

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?

One compact sentence that front-loads the purpose, but it wastes words on 'client and server side from freedailypro' marketing filler that an agent gains nothing from.

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 and zero parameter documentation, the description should at minimum state date formats and what the return value looks like (e.g., '3 years, 2 months, 5 days'). It leaves both the input contract and the output shape unspecified.

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 0% for both parameters, so the description carries the full burden. It implies a start/end date pair via 'between dates' but gives no format (ISO 8601? locale string?), and never clarifies that endDate is optional or what it defaults to when omitted.

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?

States a specific verb+resource ('Age calculator') and the computed output ('years/months/days between dates'), which is clearer than most siblings like calculate_bmi or percentage. It does not distinguish itself from near-neighbors that also compute date durations (converters_job_experience, converters_countdown), and the 'client and server side from freedailypro' branding is noise rather than purpose.

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?

There is no when-to-use guidance and no named alternative among the large calculate_*/converters_* family. An agent must infer from the name alone that this is a date-difference tool rather than an age/DOB formatter.

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