Secret Animal (hour branch)

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

The example body includes a 'time' field ('14:30:00') that is not defined in the input schema, creating a misleading contradiction. Annotations correctly mark the tool as read-only and idempotent, but the description's implied requirement for time is inconsistent with the schema, undermining trust.

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 short but includes a misleading example that does not match the schema. While efficient, the inaccuracy harms its structure and reliability.

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?

The description lacks explanation of optional parameters and does not describe the return output (no output schema). The time requirement mismatch and missing context for latitude/longitude reduce completeness for a tool with moderate complexity.

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 all parameters, so baseline is 3. The description adds a helpful example showing time format but does not explain optional parameters like latitude, longitude, or timezoneOffset. Value added is minimal.

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 computes the 'hour-of-birth branch animal' representing the 'deepest self', which distinguishes it from sibling tools like chinese_zodiac_animal and chinese_zodiac_inner_animal. The verb and resource are specific.

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 mentions 'Requires birth time' but does not provide explicit guidance on when to use this tool over alternatives, nor does it explain when not to use it. No comparison to sibling tools is given.

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