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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds the sidereal-zodiac basis and the output fields, which is useful, but says nothing about credit consumption beyond the metadata tag, timezone handling, or any computation caveats.

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 front-loaded sentences stating purpose then output, followed by compact group/cost metadata. Every element earns its place, though the return-value sentence is partly redundant given the output schema exists.

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?

An output schema exists, so return values need no prose. However, for a 15-parameter tool with low schema coverage, the description is thin: it omits any mention of required vs optional inputs, timezone/offset semantics, or the ayanamsa school choice that materially changes the result.

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% across 15 parameters, and the description compensates for almost none of it: ayanamsa, timezone, timezoneOffset, fields, precision, houseSystem and zodiacType are never mentioned. Only 'sidereal zodiac' loosely gestures at zodiacType/ayanamsa, so the heavy parameter burden is left entirely to the 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?

States a specific verb ('Calculate') and resource ('Nakshatra (lunar mansion) for each planet') plus the sidereal scope, and names the returned fields (name, pada, deity, quality). It is clear what it does, but it does not distinguish itself from the close sibling astroway_vedic_panchang_nakshatra_of_day, which also deals with nakshatras.

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 description offers no when-to-use context, prerequisites, or alternative routing. An agent must infer that this is the per-planet nakshatra placement tool and that panchang_nakshatra_of_day is the different, day-level sibling.

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