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

Annotations already declare the safety profile (readOnlyHint, idempotentHint, non-destructive, closed-world), so the description is not the main carrier here. It does add genuinely useful operational context in the cost (10 credits, Tier 1) and the required-parameter list, but says nothing about output shape or computation limits.

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 core purpose is front-loaded in one line, followed by compact bracketed metadata (group, endpoint, required, cost) and a short alias note. Nothing is padded, though the bracketed blocks are metadata rather than explanatory content.

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, and the endpoint/cost/required blocks cover the minimum needed to invoke the call. However, for a 15-parameter tool with low schema description coverage, the description does not do enough to round out the missing parameter meaning.

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% and 15 parameters exist, so the description is expected to compensate but does not. It lists the four required parameters (date, time, latitude, longitude), which merely repeats the schema's required array, and leaves the remaining eleven parameters undocumented.

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?

Names the specific technique (Dorothean triplicity rulers) and its scope variants (day/night/common), which is a concrete astrological resource rather than a tautology. It also explicitly identifies itself as an alias of a named sibling, aiding disambiguation, though it does not explain how it differs from other Hellenistic triplicity-family tools.

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 or when-not-to-use guidance and no selection criteria against alternatives. The alias note tells the agent this is interchangeable with one sibling, but nothing indicates the context in which a caller should reach for this technique.

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