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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds genuine behavioral value beyond that by disclosing the returned content (current Mahadasha/Antardasha plus the full sequence) and the computation basis (BPHS Ch.46-49, Swiss Ephemeris), which signals deterministic, classical-rule-based output rather than generative text.

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 tight sentences with no filler; the scope of returned data is front-loaded and the provenance/methodology is appended as a short clause. Nothing can be removed without losing information.

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?

With no output schema, the description bears the burden of describing returns, and it does so by listing the three data sets produced. Combined with a fully documented 7-parameter schema and complete annotations, an agent has what it needs; only the exact response shape (nesting/format of the period list) remains unspecified.

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%, including patterns, ranges and the helpful note that 12:00 is conventional when birth time is unknown, so the schema carries parameter semantics entirely. The description adds nothing about date/time/lat/long inputs, so the baseline 3 applies.

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?

The description names a specific domain resource (Vimshottari Mahadasha/Antardasha timeline) and enumerates exactly what it produces: current periods, all Antardashas of the running Mahadasha, and the full Mahadasha sequence. This is clearly distinct from siblings like kundali_milan or panchang_today. It stops short of naming a sibling it replaces or contrasting with any related timing tool, so it does not reach a 5.

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 explicit when-to-use statement, no prerequisite (e.g. that a birth date/time/place is required), and no alternative tool named for related queries. The agent must infer applicability purely from the term 'Vimshottari Dasha', which is specialized domain vocabulary.

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