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 value the annotations do not: an explicit cost of 10 credits (Tier 1) and the Pet Astrology grouping, which matters for a paid metered API. It still says nothing about rate limits, latency, or output shape, so it sits at a solid middle.

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 terse fragments with the core capability front-loaded and zero waste; the bracketed group and cost metadata are compact and skimmable. It is efficient rather than padded, though the brevity edges toward under-specification.

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 not be described, and the 100% schema coverage plus safety annotations carry most of the weight for this simple read-only tool. The remaining gap is the absent usage routing versus siblings, which leaves the description only minimally complete.

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 100%, so the schema already documents the birth-data body, fields, precision, and the nested gender filter thoroughly. The description only echoes the gender filter and adds no date/time/coordinate or precision meaning beyond the schema, which is the expected baseline when the schema does the heavy lifting.

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 concrete output (sign-aligned name suggestions) and an input modifier (optional gender filter), which is more informative than a tautology. However, it does not distinguish this tool from the large set of sibling pet tools (e.g. astroway_pet_sun_sign_meaning, astroway_pet_temperament), so an agent cannot tell from the text alone why it would pick this over them.

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 when-to-use guidance, no prerequisites, and no mention of alternatives among the ~30 sibling tools. The only actionable hint is that the gender filter is optional, which is a parameter note rather than usage guidance.

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