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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful operational context beyond annotations — the group (Vedic) and cost (20 credits, Tier 2) — but says nothing about output shape, rate limits, or whether ayanamsa choice affects the result.

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?

Extremely compact and front-loaded: the definition of the yoga and its formula come first, metadata last. Nothing is padded, though the formula sentence is terse enough to be cryptic to a non-specialist.

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 15-parameter astrological computation with 33% schema coverage, the description is too thin. Although an output schema exists (so return values needn't be explained), the agent gets no help on the required geotemporal inputs or on how this differs from its many Panchang siblings.

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 only 33%, and the description contributes zero parameter guidance — nothing about the required date, time, latitude, or longitude, nor the effect of ayanamsa or timezone on the computed yoga. With low coverage the description is expected to compensate and does not.

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 resource — the Surya-Chandra Yoga of the Panchang — and even supplies the computation (Sun+Moon longitudes divided by 360/27), so the agent knows exactly what is produced. It does not, however, distinguish this from the sibling Panchang elements (tithi, karana, hora, etc.), leaving disambiguation to the tool name.

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 statement of when to call this tool, no prerequisites, and no reference to the other Panchang tools. The agent must infer that this returns one of the five Panchang limbs from the name alone.

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