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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds genuinely new behavioral facts: the recursive proportional split formula (parent_years × sub_planet_period / 100), the cost (20 credits, Tier 2) and the endpoint. It stops short of describing failure modes when no MD is running at targetDate.

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?

Two short sentences plus bracketed metadata lines; the definition and formula come first, routing/cost metadata after. Nothing is padded, though the formula sentence is of marginal use to an agent selecting the tool.

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 no explanation, and annotations cover the safety profile. Cost, endpoint and level semantics are present; the remaining gap is disambiguation from the four sibling Shatabdika levels and the other dasha systems sharing this naming pattern.

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 100%, so the birth-data body, fields and precision are already documented. The description does add meaning for targetDate, which is otherwise an undocumented pattern-only property, by stating it selects the running mahadasha — but it says nothing about targetTime or targetTzOffset.

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: the Shatabdika antardasha sub-periods of the currently running mahadasha, plus the count (7) and the selecting input (targetDate). This implicitly separates it from the _maha level and from deeper levels, though it never names pratyantar/prana/sookshma siblings explicitly.

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 only usage signal is 'at targetDate', which implies a date is required but gives no guidance on when to pick this level over _maha, _pratyantar, _prana or _sookshma, nor on the prerequisite that a running mahadasha must exist. No alternatives are named.

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