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

Annotations already declare a safe, idempotent, closed-world read, so the safety profile is covered. The description adds useful context beyond that: the default of targetDate to today UTC, the fixed cardinality of nine returned ADs, and the credit cost. It does not add richer behavioral detail (e.g. what happens when targetDate falls outside any MD), which keeps it at a solid 3.

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-loaded with the term, then the default, the return shape, and the proportional formula, followed by compact group/cost metadata. The formula is arguably decorative, but the whole thing is short and every sentence carries some signal.

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-value detail is not the description's burden, and the group/cost lines round it out. The main gap is the absence of sibling routing for the five nested dasha levels, which for this dense family of tools would help an agent pick correctly.

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 effectively 100%, with birth data and target fields heavily documented in the schema, so the baseline is 3. The description only adds the default for targetDate, which the schema does not restate, and gives no further meaning for the birth-data 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?

States a concrete verb+resource: it returns the nine Antardashas covering the currently active Mahadasha, and defines AD as a sub-period within an MD. This clearly places it at one level of the Vimshottari hierarchy, but it never names the adjacent siblings (vimshottari_maha, vimshottari_pratyantar/sookshma/prana) to make the level choice unambiguous.

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?

Usage is implied by the definition of the dasha level, and it helpfully states targetDate defaults to today UTC, so an agent can infer when to call it. However, there is no explicit when-to-use/when-not, no routing to the maha or pratyantar sibling for a different time resolution.

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