Rahu Kaal

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds meaningful context beyond those: it computes three kaal bands, depends on location and date, and includes a local-time 'active now' check. It could mention more about error behavior, but the docs link and output schema cover some of that gap.

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 organized into distinct, purposeful sections: core behavior, workflow, input contract, exclusions, and documentation link. The central behavior is front-loaded, and no sentence is filler or tautology.

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 nested-location tool with an output schema and strong annotations, the description is nearly complete: it covers workflow, sibling differentiation, validation behavior, and points to the full contract. It loses a point because the ambiguous 'place name' alternative in the location schema is not clarified in the description, and the exact required coordinates/date are only implicitly referenced.

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 baseline is 3. The INPUT CONTRACT adds modest value by noting that LocationInput validates the date pattern and coordinates locally. However, the description does not resolve the schema's confusing 'location' property description that mentions a place-name alternative while the schema actually requires lat, lon, and date.

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 first sentence names three specific outputs (Rahu Kaal, Gulika Kaal, Yamaganda Kaal intervals) plus an active-now status flag, and ties the computation to diurnal length and location. The DO NOT CONFUSE section explicitly distinguishes it from choghadiya and panchanga, so an agent can identify it without opening the schema.

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?

WORKFLOW states this tool is standalone with no prerequisite, and AFTER names choghadiya as the broader alternative. DO NOT CONFUSE further gives two exclusions with reasons, making when-to-use and when-not-to-use explicit.

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