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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds meaningful domain behavior: the block-based nakshatra mapping anchored at Ardra and a per-chart applicability flag per BPHS 46.23, which the agent could not infer from annotations. It does not, however, describe output shape or computational edge cases.

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?

Four compact clauses, each carrying real information (system, planets/periods, mapping, applicability) with the group and cost tag at the end. No filler, but slightly dense in the period-list clause; front-loading the system name is well done.

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?

For a read-only dasha calculation tool with an output schema present and rich nested input documentation, the description supplies the domain-specific knowledge an agent needs to select it and to understand the applicability flag. It omits time-range/output-shape details, but those are covered by the output schema and the shared birth-data schema.

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 schema is heavily self-documented (date, time, latitude, longitude, timezone, ayanamsa, houseSystem, plus compact-mode fields and precision). The description adds nothing about the body/fields/precision parameters, so with near-complete schema documentation the baseline of 3 is correct.

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 the exact system (108-year Ashtottari Dasha), the tradition (Ardradi), the planet set with their period allocations, and the Ketu exclusion. This distinguishes it clearly from the many sibling dashas (Vimshottari, Yogini, Shodashottari, Chara, Kalachakra, etc.) because it names the specific dasha length and planet-period scheme.

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?

The description conveys context (which dasha system, which tradition) and the applicability rule from BPHS 46.23 (day Krishna OR night Shukla), which tells the agent when this dasha applies. However, it doesn't explicitly say when to use this tool vs the sibling Mahadasha tools (e.g., vimshottari_maha) or the antar/pratyantar/sookshma/prana sub-levels of the same system.

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