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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds value beyond that: the default targetDate of today UTC, the exact arithmetic used to derive the sub-periods, and the 20-credit Tier 2 cost, which an agent needs for budgeting. It does not describe pagination or return shape, but an output schema exists so that is not required.

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?

Front-loads the identity of the dasha level, then the qualifying detail (default date) and the formula; the group/endpoint/cost block is compact metadata. No filler sentences, though the alphabetical formula is slightly dense for a description opener.

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?

What the tool returns is covered by the output schema, and cost, endpoint and default date are given, so an agent has enough to invoke it. What is missing is the routing context across the unusually deep dasha family (maha/antar/pratyantar/sookshma/prana for ten different systems) — the description gives no help choosing this level or this system over the ~50 sibling dashas.

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 nested birth-data fields are heavily documented in the schema, so the schema is doing the heavy lifting. The description only adds the default behaviour of targetDate; it says nothing about targetTime, targetTzOffset, fields or precision. Baseline 3 is appropriate.

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 a specific dashas level and resource: Ashtottari Antardasha, defined as the 8 sub-periods of the running Mahadasha at a target date. The formula (P.years × Q.years / 108) pins down exactly which level of the dasha hierarchy this computes, which is more than a generic restatement. It stops short of explicitly naming sibling levels (pratyantar/sookshma/prana) to disambiguate the hierarchy, so it is clear but not fully sibling-differentiated.

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 statement of when to choose this level over maha, pratyantar, sookshma or prana. The only usage-adjacent detail is that targetDate defaults to today UTC. The agent must infer from the name which dasha depth it needs, with no alternatives or exclusions offered.

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