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

Annotations already carry the full safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real behavioral content beyond them: the returned count (8 sub-periods), the recursive proportional split formula (parent_years × sub_planet_period / 116), and the billing tier (20 credits, Tier 2). It does not disclose failure modes, such as what happens when targetDate falls outside the running MD.

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 tool's identity and behavior in two compact sentences, with endpoint/group/cost metadata clearly bracketed below. No filler. The formula parenthetical is terse but functional rather than verbose.

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 nested input schema is richly documented, so return values and parameters are covered elsewhere. What is missing is the disambiguation context an agent needs to pick this tool over its numerous dasha siblings; for a leaf computation tool it is adequate but not self-sufficient.

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 already documents every field in detail, so the baseline is 3. The description only lightly reinforces `targetDate` as the anchor for the running MD and adds nothing about `fields` or `precision` beyond what the schema states.

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 resource (Shodashottari Antardasha) and scopes it concretely: '8 sub-periods of the running MD at targetDate.' An agent knows it returns a computed period set, not a chart or a lookup. However, it never distinguishes itself from the near-identical siblings (pratyantar, prana, sookshma, maha), so the agent must supply the domain knowledge of what an 'antar' level is.

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 when-to-use, when-not-to-use, or alternatives statement. In a family of 60+ dashas tools split by both system (ashtottari, chara, vimshottari, yogini...) and depth (maha/antar/pratyantar/prana/sookshma), the absence of any routing guidance is a real gap. The agent has to infer selection purely from the name.

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