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

Annotations already declare this a safe, idempotent, read-only, non-open-world read. The description adds genuine behavioral value beyond that by disclosing non-obvious output traits: boundary warnings and unresolved lineage-specific source keys, which signal partial/uncertain results that an agent should surface rather than treat as definitive.

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 the content enumeration front-loaded and the sibling differentiation placed last. Every clause earns its place, though the run-on list of outputs is dense.

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?

Return values need not be explained since an output schema exists, and annotations cover the safety profile. But for an 8-parameter tool with a required anyOf alternative between 'place' and explicit coordinates, the absence of any location-input guidance is a real completeness gap for an agent trying 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?

Schema description coverage is only 38% across 8 parameters, and the description says nothing about any of them. In particular it ignores the anyOf constraint that location is given either as 'place' OR as latitude+longitude+timezone, which is the single most important invocation decision for this tool. The description does not compensate for the coverage gap.

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 the exact resource ('natal Panchanga') and enumerates the specific outputs (Vara, Tithi class, Nakshatra lord, Yoga, Karana, Paksha Bala). It also explicitly separates itself from the sibling 'daily Panchanga', so an agent can distinguish it from get_panchanga without opening either 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?

The closing sentence 'This is distinct from daily Panchanga' gives a clear routing signal away from the sibling get_panchanga for daily use. However, it stops short of stating explicit prerequisites (e.g., 'use when the chart is already cast') or when-not conditions, so it is clear context rather than full when/when-not guidance.

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