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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior. The description adds useful algorithmic context by explaining that distance is computed exactly from hour angle and altitude rather than a discretised polyline, and that it ranks supportive versus challenging influences.

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 purpose is front-loaded in the first sentence, but the description then spends significant space on a technical formula and ends with a truncated phrase ('Supportive and challengin…'). It is not wasteful, but not tightly structured either.

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?

With an output schema, rich annotations, and full schema descriptions, the main missing piece is usage guidance relative to sibling tools. For a specialized ranking tool, the description is adequate but leaves routing decisions to inference.

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 100%, so every parameter already has documentation. The description mentions the 19 life categories and supportive/challenging ranking, but adds no syntax or format details beyond what the schema 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 states a specific verb and resource: 'Rank cities against the astrocartography lines of a chart for one of the 19 life categories.' That is clear and actionable, but it does not explicitly differentiate this tool from close siblings such as astroway_geo_acg_by_category or astroway_geo_acg.

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?

The description gives no when-to-use, when-not-to-use, or alternative-tool guidance. An agent must infer from the name and sibling list whether this or another ACG endpoint is appropriate.

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