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

Beyond the existing readOnlyHint/idempotentHint annotations, the description reveals the mod-90 wrapping behavior, guarantees exactly 52 seats, lists the returned fields, and even furnishes the fixed seat positions. It also discloses that no birth date or PII is involved, giving the agent a precise behavioral contract.

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 text is front-loaded with the operation and resource, and each subsequent clause adds a distinct fact: no PII, exclusions, return shape, fixed seats. There is no filler or repeated content.

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, the description furnishes the essential return contract, field names, and fixed-seat detail. It omits explicit handling for negative age_no, but that is a minor gap for a one-input read-only getter; this is still highly complete.

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?

The input schema already documents `age_no` with its range and wrapping behavior in 100% coverage. The description repeats the same 0..89 and mod-90 constraint rather than adding genuinely new meaning; it does not explain, for example, what happens with negative `age_no` values.

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 action ('USE for one Magian Grand Solar Age board') and the resource keyed by `age_no`, and it enumerates exactly what is returned (a 52-seat board with card ref, position, planet coordinates, and fixed-card flag). It also distinguishes itself from get_age_spread and 'Long Range Journey', so the purpose is 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?

It gives an explicit when-to-use ('for one Magian Grand Solar Age board by age_no') plus two explicit exclusions ('NOT Long Range Journey; NOT get_age_spread person slice'). An agent can route to this tool or away from it without opening any schema.

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