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

With no annotations, the description carries the full burden and does disclose the casting mechanic (six tosses, bottom line first) and the complete result shape (primary hexagram, changing lines, relating hexagram, meaning links). It omits whether the cast is random/stateless and whether repeated calls yield different results, which matters for a divination tool.

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?

Three tight sentences: method first, return value second, usage rule last. No filler and nothing redundant with the title.

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 two-parameter, zero-required tool with no output schema, the description usefully enumerates what comes back and how the hexagram is derived. Minor gaps remain around non-determinism and whether the question influences the cast, but an agent has enough to call it 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 100%, including a detailed language enum explanation and the note that question is echoed back only and not stored, so the schema already does the heavy lifting. The description adds no parameter-level meaning beyond it; baseline 3 applies.

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?

States a specific verb (cast) and resource (I Ching reading) plus the exact method (traditional three-coin, six tosses, bottom line first), which is far more informative than the title alone. It does not explicitly differentiate from the sibling get_hexagram (lookup of a known hexagram), leaving that distinction to be inferred.

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?

"Use this instead of making up a hexagram" gives clear, actionable usage guidance and implicitly rules out fabrication. It stops short of naming alternatives or exclusions, such as when to use get_hexagram instead or whether repeated casts are meaningful.

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