Phase Return

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

The description adds value beyond annotations by explicitly stating the credit cost (100 credits, Tier 4) and providing an example request. The annotations already declare readOnlyHint=true, so the description aligns and adds cost context.

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 two sentences plus a group/cost line and an example. The purpose is front-loaded, and the example is directly useful. No extraneous text.

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?

Given the tool's complexity (one nested parameter), the schema and annotations provide 100% coverage. The description adds purpose, an example, and cost info. Considering the absence of an output schema, the description is sufficient for selection and basic use.

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 the baseline is 3. The description's example request shows parameter format, but does not add new semantic meaning beyond the schema's own descriptions.

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 the tool finds dates when a planet returns to its same synodic phase relative to the Sun, with specific examples like Venus heliacal rising and Mars retrograde station. This verb+resource combination is precise and distinguishes it from sibling tools such as 'planetary_return' or 'transits'.

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 a group label and cost, and includes an example request, but does not explicitly state when to use this tool versus alternatives. The examples hint at usage contexts, but no direct guidance on exclusion or comparison with similar tools.

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