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

Annotations already declare readOnly=true, idempotent=true, destructive=false and openWorld=false, so the safety profile is fully covered. The description adds genuinely useful behavioral context — that the split is recursive and proportional (parent_years × sub_planet_period / 116) — which is the one thing structured fields cannot convey. It stops short of describing output shape or edge cases, but the output schema covers returns, so a 3 is fair.

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 tight sentences, front-loaded with the technique and scope, followed by the grouping and cost tags. No filler. The formula sentence is dense but earns its place by defining the calculation.

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 and full annotations exist, so return values and safety need not be restated. What is missing for a 5 in this dense tool family is disambiguation and usage guidance relative to the other shodashottari and antar siblings — the one gap that structured data cannot fill.

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% and the body schema is richly annotated, so baseline 3 applies. The description does explain the semantics of targetDate (the moment at which the running MD is evaluated), but adds nothing about the birth-data body, fields, or precision 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?

Names the exact technique with a specific verb+resource: it returns the 8 Antardasha sub-periods of the running Mahadasha evaluated at targetDate. This implicitly separates it from shodashottari_maha (the MD itself) and the deeper pratyantar/prana levels. However, it never names a sibling or explicitly states the level in the hierarchy, so an agent must infer the distinction from the tool name.

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. Given the very large sibling family (maha/antar/pratyantar/prana/sookshma across a dozen dasha systems), the description should say something like 'use this for level-2 detail inside the Shodashottari MD; for level 3 use shodashottari_pratyantar'. Nothing here routes the agent.

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