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

Annotations already declare readOnly, idempotent and non-destructive, so safety is covered. The description adds genuinely new operational context: cost (10 credits, Tier 1) and grouping, plus a note that the result is the 9-year personal-evolution cycle. No rate limits or auth notes, but the credit price is real value an agent needs for planning.

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 tight sentence front-loads the purpose, and the bracketed metadata lines are cheap. The group/cost boilerplate is formulaic but not wasteful for an agent that must budget credits.

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 described, and annotations cover the safety profile. The remaining gap is the undocumented required inputs, which for a name-sensitive numerology calculation is a meaningful omission for an otherwise simple single-purpose tool.

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 40% – only `fields` and `precision` are documented, while the three required params (`name`, `date`, `year`) have no descriptions. The description gestures at 'a given calendar year' but never clarifies whether `name` is a birth name at birth or a current name, which materially changes the numerology result.

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 Personal Year number for a given calendar year') and adds a system qualifier ('Kabbalistic (Mathers strict)') that separates it from the chaldean/pythagorean/vedic siblings. It does not, however, explain how 'strict' differs from the plain kabbalistic sibling, which is the nearest neighbor.

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?

No when-to-use guidance, no prerequisites (name format, birth date vs. current name), and no explicit routing to alternatives despite ~70 sibling tools that compute the same personal-year quantity in other systems. The only implied usage is 'you have a name and a year'.

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