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

Annotations already declare readOnlyHint, idempotentHint, closed-world, and non-destructive behavior, so the bar is lower. The description adds meaningful behavioral context not in annotations: the cost ('20 credits (Tier 2)') and the recursive calculation method. It still omits auth needs and rate limits, but the cost disclosure is practical operational transparency.

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 short sentences front-load the purpose and formula, followed by compact group/cost tags. Every phrase earns its place, with no filler or repetition.

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 values need not be explained, and annotations cover the safety profile. The description supplies purpose, targetDate, formula, and cost, but lacks sibling routing and prerequisite context; adequate given the structured fields, though not fully self-contained for tool selection.

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%, so the schema already documents all three top-level parameters and nested birth-data fields. The description only clarifies that targetDate anchors the running mahadasha, adding minimal meaning beyond the schema; body fields and compact-mode parameters are left entirely to structured definitions.

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 specific dasha type and level ('Tribhagi Antardasha'), the output scope ('9 sub-periods of the running MD at targetDate'), and the computation basis. It differentiates implicitly from maha/pratyantar/prana via 'Antardasha' and '9 sub-periods,' but does not name any sibling tool explicitly.

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 or alternatives are mentioned. It does not explain how this differs from sibling tools such as tribhagi_maha, tribhagi_pratyantar, tribhagi_prana, or other dasha systems like vimshottari_antar. The only contextual cue is 'at targetDate,' which implies the evaluation moment but gives no routing rules.

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