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

No annotations are provided, so the description carries the burden. It discloses the detailed contents of the response (judgment, image, Tuan commentary, etc.) and notes 'available' source material, indicating conditional presence. It does not mention error handling, but for a read-only lookup, this is reasonably transparent.

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 a single, front-loaded sentence that starts with the action and resource. It lists many components in a structured way, making it dense but efficient. It could be slightly more concise by trimming the list, but it is not overly verbose.

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?

For a tool with no output schema, the description provides a thorough list of return fields and mentions language coverage, giving a clear sense of what to expect. It does not detail behavior around the compact parameter, but the schema covers that. Overall, it is sufficiently complete for a lookup 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 descriptions cover 67% of parameters (number and compact), while locale lacks a description. The description hints at language options via 'Chinese and English source material' but does not explicitly explain the locale parameter. It adds some context beyond the schema but does not fully compensate for the uncovered parameter.

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 returns the full classical sources for a hexagram by number, enumerating specific components like judgment, image, and commentaries. This distinguishes it from sibling tools like cast_hexagram and divine, which involve casting or divination.

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 usage for looking up a hexagram's classical material by number, but it does not explicitly state when to use this tool versus alternatives like lookup_yilin or cast_hexagram. No exclusions or alternative guidance is provided, leaving the context somewhat implied.

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