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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new operational facts — cost of 10 credits (Tier 1) and the endpoint — but says nothing about return shape, edge cases, or what a call produces beyond the concept label. Modest added value over annotations.

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 concept is front-loaded in the first line and the bracketed metadata block is scannable with zero filler. It is tight, though arguably too terse for a 15-parameter tool.

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 complex 15-parameter tool with three enum sets and a close sibling, the description is far too thin: no usage context, no differentiation, no parameter explanation. An output schema exists so return values need not be described, but the input-side and selection-side gaps remain substantial.

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 carries a heavy burden and does not meet it. It merely restates the four required fields already listed in the schema, and explains none of ayanamsa, zodiacType, houseSystem, timezone, fields, or precision.

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 fragment 'Duodecima: 2.5° micro-sign per planet' names the technique and its output granularity but contains no verb describing the operation and relies on specialized jargon. It fails to distinguish itself from the sibling astroway_hellenistic_greenbaum_dodekatemoria, which the agent will likely confuse with it. Purpose is implied rather than stated.

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 guidance on when to use this tool versus the very similar dodekatemoria sibling, nor any prerequisite or context statement. The bracket summary supplies required fields and cost but nothing about selection conditions.

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