Lunar Return

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: the cost (50 credits, Tier 3), the POST endpoint despite read-only semantics, and that the response is a full chart rather than a bare timestamp.

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?

Two sentences, front-loaded with the outcome and immediately followed by what is returned. The bracketed group/endpoint/cost metadata is compact and scannable. Nothing is redundant, though the body is quite terse for a tool with this much nested input.

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 no explanation, and the input schema fully documents the birth-data and afterDate parameters. The remaining gap is the search horizon (how far forward it scans for the return) and what happens when none is found, but the essentials for calling the tool are present.

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%, with the nested body model thoroughly documenting date, time, coordinates, timezone handling, ayanamsa and houseSystem. The description adds nothing about the afterDate/afterTime search-window parameters, so it neither compensates nor detracts; baseline 3 applies.

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?

States a specific verb and resource: find the next date the Moon returns to its natal longitude, and that it returns a full lunar return chart. The purpose is unambiguous. It does not, however, distinguish itself from close siblings such as astroway_prognostics_solar_return or astroway_prognostics_planetary_return, which an agent comparing return-type tools would want.

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 phrasing 'Find the next date...' implies a predictive/timing use case, but there is no explicit when-to-use guidance, no prerequisites, and no naming of alternatives like the solar or planetary return tools. The agent must infer everything about tool selection from the name alone.

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