Weekly Horoscope

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

Annotations already declare readOnly/idempotent/non-destructive/no-open-world, so the safety profile is covered. The description adds genuinely useful behavioral context — the 50-credit Tier 3 cost and that the week's ingresses, stations and lunar phases appear both in `events` and the prose — but says nothing about rate limits, caching, or what happens when `date` is omitted.

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?

Front-loaded one-sentence purpose followed by compact operational metadata (group, endpoint, required field, cost). Tight overall; the 'same shape as the daily one' phrasing is efficient but slightly circular for a reader who hasn't seen the daily tool.

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 needn't be explained, and the `events` behavior is noted. However, for a 7-param tool at 43% schema coverage, missing guidance on `date` semantics and the cost trade-off against daily/monthly leaves real gaps.

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?

Seven parameters with only 43% schema description coverage, and the description mentions only that a zodiac sign is needed. The undocumented `date`, `language` and `disclaimer_inline` parameters get no explanation of defaults or behavior in the description, so it fails to compensate for the coverage gap despite the rich enum options.

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 resource and time granularity ('Weekly horoscope for a zodiac sign') and clarifies the payload ('the week's ingresses, stations and lunar phases in `events`'). It does not explicitly name horoscope_daily/monthly/yearly as siblings, so the differentiation is implied by 'weekly' rather than stated.

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 same shape as the daily one' gives implicit context that a daily variant exists, but there is no explicit when-to-use guidance (e.g. pick weekly for week-ahead planning vs daily for today) nor any exclusion or alternative named.

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