lookup_hexagram

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

No annotations are provided, so the description carries the full burden. It correctly implies a read-only lookup operation, but does not disclose any additional behavioral traits such as data sources, performance, or error conditions. It is adequate but not comprehensive.

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 very concise with a clear header and bullet-like parameter list. Every sentence serves a purpose, and there is no redundant or unnecessary 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?

The tool is simple, with only two required parameters and an output schema likely covering return values. The description fully explains the input parameters and the purpose, making it complete for effective 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?

The schema has 0% description coverage, but the tool's description provides detailed semantics for both parameters: stem accepts Chinese, pinyin, or index; branch accepts Chinese, pinyin, animal, or index. This adds significant value beyond the schema's empty definitions.

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's purpose: looking up a Xuan Kong Da Gua hexagram for a stem-branch pillar. It specifies the exact resource (hexagram) and action (look up), and it is easily distinguishable from sibling tools like get_daily_pillars or get_natal_chart.

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 does not provide any guidance on when to use this tool versus alternatives. It lacks information about prerequisites, preferred scenarios, or when not to use it. The sibling tools are listed but no comparisons or exclusions are given.

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