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

Annotations already flag readOnlyHint and idempotentHint, and the description adds valuable behavioral context beyond that: it explicitly states 'Data only — no interpretation is added,' explaining that the tool returns computed periods without interpretive commentary. It also discloses the two computational bases for Sade Sati and the structure of the periods, which is exactly the kind of beyond-schema behavior an agent needs to know.

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?

The description is long but every sentence carries information about output structure, naming conventions, or behavioral boundaries. It is front-loaded with the core purpose, then organized by key output groups, and ends with an explicit data-only caveat. Nothing feels wasted, and the detailed structure compensates for the lack of an output schema.

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 available, the description carries the full burden of explaining return values, and it does so thoroughly: it names the main keys, describes degree-based vs sign-based Sade Sati, lists the phases, and clarifies that each period contains startDate, endDate, and a description. Given the complexity of the tool and the read-only annotations, this is complete enough for an agent to call it 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?

Input schema coverage is 100%, so every parameter already has a meaningful description. The tool description does not add new parameter-level semantics, but it does clarify the conceptual purpose of some inputs by referencing the natal Moon and Ascendant, which helps connect the parameters to the computed output. This matches the baseline for a fully documented schema.

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 opens with a specific verb and resource: 'Return Saturn's Sade Sati and related transit windows for the chart, with dates.' It goes on to enumerate exact sub-results (degreeBased, signBased, moonTransits, ascendantTransits), making the tool's scope unmistakable and clearly distinct from sibling transit tools like get_gochara or get_planet_ingress.

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?

Although the description does not explicitly name alternative tools or exclusion criteria, it provides a rich, concrete inventory of what this tool returns — Sade Sati periods, Moon transits, and Ascendant transits — so an agent can infer when it is the right choice. It does not go as far as saying 'use X instead when Y,' but the practical context is very clear.

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