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

Annotations already declare this a read-only, idempotent, non-destructive call, so the safety profile is covered. The description adds genuine domain context the annotations cannot: the fixed 9-lord ordering, the 120-year cycle length, the nakshatra-lord starting rule, and the truncation of the first period. The stated 20-credit (Tier 2) cost is also operationally useful.

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 dense sentences front-load the definition, followed by compact group/endpoint/cost metadata. Little waste, though the planetary list and the truncation rule could be trimmed without losing meaning.

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?

The output schema covers return values and the schema covers all parameters, so the description only needs to orient the agent. It does so adequately for the computational definition, but is silent on the one thing a sibling-heavy namespace demands: which dasha depth to request and why.

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 object plus the fields/precision compact-mode parameters are thoroughly documented in the schema itself. The description adds no parameter-level meaning (e.g. how ayanamsa or houseSystem interact with dasha computation), so the baseline of 3 applies.

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 precisely what is computed: the top-level Vimshottari Mahadasha sequence, with its 9 lords, 120-year cycle, starting rule and truncation of the first period. It never names its closest siblings (astroway_vedic_dashas_vimshottari_antar/pratyantar/prana/sookshma), so an agent must infer that this is the major-period level rather than a sub-period level from the word 'Mahadasha' alone.

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 (birth date/time/coordinates are required but never mentioned), and no routing to the antar/pratyantar/prana/sookshma siblings that compute deeper levels of the same system. The agent gets domain vocabulary but no decision guidance.

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