ephemeris_lunar_return

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

Beyond readOnlyHint=true, the description adds the periodic cycle (every 27.3 days) and credit cost, providing useful behavioral context not in 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 description is reasonably structured but somewhat verbose with examples and credit cost details. Could be more concise while retaining clarity.

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?

No output schema exists, but the description does not explain the return value format. For a tool computing a date/time, the output is somewhat predictable, but more detail would improve completeness.

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 coverage is 100%, and the description enhances understanding with examples for birth_datetime and target_datetime. It clarifies default behavior for target_datetime, adding value over the schema.

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 explicitly states it calculates the exact Lunar Return date/time when the Moon returns to its natal ecliptic longitude, used for casting monthly Lunar Return charts. This clearly distinguishes it from sibling tools like ephemeris_solar_return.

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?

Provides examples and default behavior for target_datetime, and mentions credit cost. However, it does not explicitly specify when not to use this tool or compare with alternatives like solar return.

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