predict_moon_phases

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

No annotations are provided, so the description carries full burden. It states it provides exact dates and times and mentions astronomical accuracy, but does not disclose timezone, output format, or any assumptions or limitations. This is adequate but not thorough.

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 four sentences, well-structured: first states purpose, second details output, third gives use cases, fourth adds quality note. It is concise but could be slightly more efficient.

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 low complexity (2 simple params, no output schema), the description covers purpose and use cases but lacks details on output format, timezone, precision, or validity constraints. It is not fully complete for an agent to understand all implications.

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% with descriptions for both parameters. The description adds that the tool returns exact dates and times but does not provide additional semantics beyond the schema. Baseline score of 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 the tool predicts and lists major moon phase transitions within a date range, using verbs 'predicts' and 'lists' with a specific resource. It distinguishes itself from sibling tools like get_moon_phase or get_moon_calendar by focusing on all transitions over a range.

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 guidance on when to use the tool (planning activities, scheduling observations, understanding lunar cycle) but does not explicitly mention when not to use it or compare to alternatives like get_moon_phase or get_moon_calendar. The context is clear but lacks exclusions.

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