Dashas: Sthira Antardasha

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful context beyond that: the equal-split division method, the dependence on the running mahadasha anchored at targetDate, the endpoint, and a cost of 20 credits (Tier 2), which matters for budget-aware agents. It does not discuss determinism across ayanamsa choices or error behavior, which keeps it below 5.

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 one substantive sentence leads with the tool's identity and the computation, followed by a compact metadata block (group, endpoint, cost). Nothing is padded, though the brevity leaves the sibling-routing question unanswered rather than intentionally excluded.

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 and the input schema is richly annotated, so the agent can call it correctly without more parameter prose. However, in a family of forty-plus dasha tools spanning Sthira/Vimshottari/Chara/Yogini and five subdivision depths, the description does not supply the disambiguation an agent needs to pick this one confidently.

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 body schema documents birth data, timezone handling and house system in detail, so the baseline is 3. The description only echoes targetDate and adds no syntax, format or defaulting information beyond the schema.

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 specific dasha level (Sthira Antardasha) and states the computation plainly: equal-split sub-periods of the running mahadasha at targetDate. That tells an agent it is the second-order subdivision, distinguishing it from sthira_maha. It does not explicitly differentiate from sthira_pratyantar, sthira_sookshma or sthira_prana, which an agent unfamiliar with Vedic dasha hierarchy would need.

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 statement of when to reach for this level versus the other Sthira levels or versus vimshottari_antar/chara_antar. The only routing hint is implicit in the word 'Antar'. Nothing says what prerequisites exist (e.g. a birth chart plus a target date) or when the tool would be the wrong choice.

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