get_moon_sign

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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds valuable non-obvious behavior: it explicitly preserves uncertainty about which Moon sign applies when the Moon changed signs during a date with an unknown birth time. This is exactly the kind of behavioral context the structured fields do not provide.

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 entire description is one efficient sentence. It front-loads the primary action—'Calculate the Moon sign'—and then adds the important uncertainty caveat without wasting words.

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 rich annotations and existing output schema, the description is nearly complete for safe invocation. The only meaningful gap is the lack of explicit guidance about when to choose this over sibling tools, and the latitude/longitude semantics are left to the schema's bare numeric constraints. Overall, an agent has enough to call the tool correctly.

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 71%, which is moderate. The description's mention of 'unknown birth time' maps meaningfully to the unknown_time parameter and clarifies its purpose. However, it does not compensate for the bare latitude and longitude parameters, which still lack schema descriptions and are not explained in the description.

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 uses a specific verb and resource: 'Calculate the Moon sign'. It also adds a distinguishing behavioral nuance—uncertainty preservation when the Moon may have changed signs—which separates it from general horoscope tools like calculate_birth_chart or get_big_three.

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 implies when to use this tool: when the Moon sign is needed, especially with an unknown birth time. However, it does not explicitly name alternatives or state when not to use it, even though sibling tools like get_big_three and calculate_birth_chart overlap in domain. The usage context is present but not made explicit.

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