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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful operational context the annotations do not: cost (10 credits, Tier 1), the endpoint, and the group. It stops short of describing anything about the computation or output beyond annotations, so it is adequate but not rich.

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 compact and front-loaded: one content line followed by tagged metadata. The bracketed fields are scannable and every line carries information. Slightly hurt by being so terse it becomes fragmentary rather than explanatory.

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 15-parameter astrological computation tool with low schema coverage, the description is thin: it never explains why a full birth date/time/location is needed for a 'sun sign' reading, nor scopes the output. The output schema relieves it of return-value documentation, and cost/endpoint are given, but the parameter and usage gaps leave it inadequate.

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, so the description is expected to compensate for undocumented fields (city, name, date, time, latitude, longitude, cosmogram, zodiacType, houseSystem, ayanamsaId). Instead it merely restates the four required parameters already present in the schema and adds no format, unit, or coordination detail (e.g. how timezone interacts with timezoneOffset, or why lat/long are needed for a sun-sign reading).

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 is a fragment listing output content ('Personality + temperament + best-suited household') rather than a verb+resource statement. Combined with the name/title, an agent can infer it returns a sun-sign-based reading for a pet, but it never states what it computes or distinguishes the sun-sign variant from siblings like astroway_pet_personality, astroway_pet_temperament, or astroway_pet_birth_chart.

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 and no routing to alternatives, despite a dense sibling set of overlapping pet tools (pet_personality, pet_temperament, pet_communication_style, pet_birth_chart). An agent must guess whether this or pet_personality is the right call for a given request.

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