ephemeris_next_lunar_phase

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds value by noting 'Returns the exact UTC datetime, zodiac sign, and degree' and mentioning credit cost. No contradictions.

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 moderately concise, using bullet points and examples. It earns its length by offering usage examples, though could be slightly tighter. Structure helps readability.

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?

Despite lacking an output schema, the description explains the return values (datetime, zodiac sign, degree), which is sufficient. It covers credit cost and default behavior. Adequate for a simple tool.

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 well-documented parameters. The description adds example usages and clarifies output details (zodiac sign, degree), providing marginal value beyond schema. 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 explicitly states 'Find the next occurrence of a specific Moon phase after a given date', clearly identifying the action (find), resource (Moon phase), and scope (next, after date). It distinguishes from sibling ephemeris tools by being specific to lunar phases.

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 explicit guidance: '✅ USE THIS TOOL FOR: ...' with example queries. While it doesn't explicitly mention when not to use it, the examples and context make its usage clear. Lacks exclusion but overall strong.

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