ephemeris_chart_wheel

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

Annotations already mark the tool as readOnlyHint=true and destructiveHint=false, so the description correctly does not repeat that. The description adds the credit cost and notes it displays inline, but does not disclose potential error behaviors or output size limitations.

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 description is concise at four sentences plus an example. It is front-loaded with the primary purpose and quickly conveys the key information. The credit cost and example are well-placed.

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?

While the description gives a clear purpose and an example, it lacks details about output format (e.g., SVG dimensions), error handling, or limitations (e.g., only natal charts). Given the high schema coverage and sibling wealth, the description is adequate but not complete.

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?

The input schema has 100% coverage with detailed descriptions for all six parameters. The tool description adds an example showing parameter combination but does not enhance parameter semantics beyond what the schema already provides. Thus, baseline 3 is appropriate.

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 clearly states it generates a classic astrological chart wheel SVG image, specifying it includes planets, aspects, and house cusps. The tool name and description align, but it does not explicitly distinguish from sibling tools like ephemeris_natal_chart or chart_wheel_on_aspect_click, which may have similar outputs.

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 provides an example usage but fails to specify when to use this tool versus alternatives (e.g., not for bi-wheel or text-based charts). It does not mention conditions to avoid using it, such as when a different house system is needed beyond the enums listed.

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