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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context beyond annotations: a credit cost ('10 credits (Tier 1)') and the concrete endpoint, which help an agent budget and route the call.

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 substantive sentence is front-loaded, single-purpose and wastes no words. The trailing bracketed metadata block is boilerplate rather than prose, but it is compact and skimmable rather than rambling.

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?

An output schema exists, so return values need not be explained, and the description covers purpose, formula, required inputs, cost and endpoint. The remaining gap is input interpretation (whose name, birth vs current) and no note on how the result should be interpreted age-wise.

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 50% (fields and precision are documented in-schema; name and date are not). The description only repeats 'Required: name, date', adding no meaning over the schema's required array and no clarification of what form the name should take. It does not compensate for the undocumented parameters.

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 and resource ('Calculate the Maturity number'), identifies the system (Chaldean), and even gives the underlying formula (sum of Life Path and Expression), which distinguishes it from the many sibling *maturity* tools for other systems. It stops short of explicitly contrasting against e.g. pythagorean_maturity or life_path, relying on the system label alone.

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 or when-not-to-use guidance: nothing says when to pick Chaldean over Pythagorean/Kabbalistic maturity, or when maturity is preferred to its component numbers (life_path, expression). The 'activates around age 35' note is interpretive context for the number, not invocation guidance.

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