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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds only the cost disclosure (10 credits, Tier 1) and group tag, which is genuinely useful budget information but says nothing about what data is consumed or how results are shaped.

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 text is short and front-loaded with the deliverable, which is good, but it is under-specified rather than efficient — the single content line does not carry enough information to justify the omission of usage and input guidance.

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, but for a 15-parameter chart tool with 33% schema coverage the description should at least indicate that a birth date/time/place is required and how this result differs from the other pet tools. It does not.

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, and the description compensates for none of it. The four required parameters (date, time, latitude, longitude) are undocumented in both places, and the enums and compact-mode options are left entirely to the schema.

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 the deliverable ('Preferred training style + 3 tips'), so an agent knows roughly what content comes back, but there is no verb and no mention that it derives from birth-chart data, which is the tool's actual operation. It sits adjacent to siblings like astroway_pet_play_style and astroway_pet_temperament without stating how it differs from 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 statement, no prerequisites (e.g. that date/time/lat/long are required), and no routing to or away from sibling tools such as astroway_pet_play_style. The agent must infer everything about invocation context.

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