Lucky Days

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

Annotations already declare readOnly/idempotent/non-destructive and closed-world, so safety is covered. The description adds genuinely useful non-schema context: a POST endpoint (worth noting for a read-only computation) and a per-call cost of 10 credits (Tier 1). It still omits what a 'lucky day' result contains at a high level and whether the derived sign comes from the supplied date/time/location.

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?

Very short and front-loaded, with the operational metadata (group, endpoint, required, cost) compactly bracketed. Nothing is wasted, though the single semantic sentence is under-specified rather than efficient.

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 13-parameter computational endpoint in a dense sibling namespace, the description leaves too much unexplained: no mention that the sign is inferred from the pet's supplied birth moment and coordinates, no sense of output granularity, and no hint about how the sidereal/house-system options alter results. An output schema exists, which relieves it of return-value duties, but the input semantics gap remains.

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?

With 13 parameters and only 23% schema description coverage, the description needs to carry weight, but it merely repeats the required set (date, time, latitude, longitude) which the schema's `required` array already states. Nine optional parameters — name, city, ayanamsa/ayanamsaId, zodiacType, houseSystem, timezone, timezoneOffset, cosmogram — get no explanation of whether they affect the 'sign' used.

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 sentence 'Days of week traditionally aligned with the sign' indicates the output (weekday alignments for a sign), so it is more than a tautology, but it never says the sign is derived from a pet's birth data/chart, nor that this is a computed lookup rather than a static table. The '[Group: Pet Astrology]' tag is what mainly separates it from astroway_financial_lucky_day, not the prose.

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?

No when-to-use guidance at all: no statement of which pet-related question this answers, no prerequisites (does a birth chart need to be cast first?), and no named alternative among the many pet_* and *_lucky_day siblings. The only routing signal is the group tag.

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