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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context not in the annotations - the 10-credit Tier 1 cost and the Greenbaum group membership - but says nothing about output shape or what 'attributions' 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?

It is short and front-loads the only substantive clause, but the two bracketed metadata lines are boilerplate rather than descriptive content. Terseness here reflects under-specification rather than disciplined conciseness.

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, 4-required astronomical computation tool, the description is far too thin; it omits usage context, parameter semantics, and any tradition differentiation. An output schema exists, so return values need not be spelled out, but that does not offset the missing input and routing guidance.

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 must compensate for undocumented fields, and it supplies nothing about date/time/latitude/longitude or any optional parameter. It adds no semantics beyond the enum and inline descriptions the schema already provides.

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 resource (zodiacal decans) and adds a qualifier ('with attributions'), so it is slightly more than a bare restatement of the title. However, it gives no verb or computation detail and does nothing to distinguish this Greenbaum-tradition tool from close siblings such as astroway_helg_zodiacal_decans or astroway_hellenistic_hand_decanic_rulers.

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, when-not-to-use, or alternative-selection guidance at all. In a catalog with several decan/decanic-ruler endpoints, the agent is left to guess which tradition-specific tool applies.

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