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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It goes beyond typical descriptions by detailing output order ('show the classical sources first, then offer a thoughtful reflection'), philosophical stance ('Reflection, not prediction'), language support, and quota policy including what does NOT consume quota (timeout, provider failure, incomplete response, cancellation). This is exceptionally 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 relatively long but information-dense, with each sentence contributing value. It is front-loaded with purpose ('Ask the I Ching. See your next step.'), then covers behavior, name stability, languages, and quota. The sentence about the divine name being stable for client compatibility is somewhat extraneous for an agent, but not excessively 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?

Given the absence of an output schema, the description adequately outlines what the tool does and what to expect: a hexagram cast, classical sources, and a reflection. It also covers edge-related behavior (quota). It could be more explicit about the exact structure of the response (e.g., whether it includes lines, translations), but it is sufficiently complete for an agent to understand the tool's function.

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 60% (seed, question, device_id have descriptions in schema). The description adds context for locale by listing supported languages and clarifies device_id's role in quota tracking. However, it adds no direct meaning for the 'seed' and 'method' parameters beyond what the schema already states or implies (e.g., enum values).

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 function: 'Ask the I Ching. See your next step. Cast a hexagram, show the classical sources first, then offer a thoughtful reflection grounded in those sources.' It uses specific verbs (ask, cast, show, offer) and resource (I Ching), and distinguishes from siblings by emphasizing the reflective reading rather than just casting or lookup. The phrase 'Sources first. Reflection, not prediction.' further clarifies the purpose.

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 provides clear context for when to use this tool: when you want an I Ching reading with classical sources and reflection. It does not explicitly mention alternatives or exclusions relative to sibling tools (cast_hexagram, lookup_hexagram, lookup_yilin), but the use case is well implied. The quota information also gives practical usage guidance.

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