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

Annotations already establish readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful billing context ('Cost: 10 credits (Tier 1)') that is not in the structured fields, but says nothing about required birth data or what the output contains.

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?

The description is two short lines, front-loaded with the purpose followed by metadata tags, with no filler. It is efficient, though its brevity is part of the under-specification problem rather than a virtue.

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 explained. However, for a 15-parameter chart tool with low schema coverage and a crowded sibling set, the description omits input expectations, usage conditions, and sibling differentiation, leaving the agent under-equipped to invoke it correctly.

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 15 parameters and only 33% schema description coverage, the description carries a heavy burden but contributes zero parameter information. Required inputs (date, time, latitude, longitude) and undocumented fields such as city, name, cosmogram, zodiacType and houseSystem get no explanation from either source.

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 phrase 'How best to communicate with this pet' conveys the general purpose, but it lacks an explicit verb and does not differentiate itself from near-identical siblings like astroway_pet_training_style, astroway_pet_personality, or astroway_pet_temperament. An agent cannot tell from the text whether this returns advice, a chart-derived classification, or something else.

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 many pet_* siblings. The [Group: Pet Astrology] tag only categorizes the tool; it does not tell the agent when to select this over pet_training_style or pet_personality.

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