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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed world, so the safety profile is covered. The description usefully adds cost (10 credits, Tier 1) and group membership, but does not explain what a 'changing line' produces or how the transformed hexagram is derived.

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?

Extremely short and front-loaded, with the core output concept stated first and metadata tags after. Nothing is padded, though the brevity shades into under-specification rather than true economy.

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?

An output schema exists, so return values need not be explained, and there are no required parameters. However, for a divination tool with an unexplained seed input, the description leaves the agent without enough conceptual grounding to choose or invoke it confidently.

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?

Coverage is only 67%, and the single undocumented parameter is `seed`, which is the semantically critical input for a divination tool (it controls determinism of the cast). The description says nothing about any parameter, so it does not compensate for the gap the schema leaves.

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 fragment 'Primary + transformed hexagrams' identifies the resource (hexagrams) and the distinguishing feature (a transformed hexagram produced by changing lines), which loosely separates it from astroway_iching. But it never states a verb or action ('cast', 'generate', 'read') and reads as an output label rather than a purpose statement.

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?

There is no when-to-use guidance, no prerequisites, and no mention of the sibling I Ching tools (iching_throw_coins, iching_by_question, iching_daily, plain iching). The only routing signal is the implicit 'changing lines' concept in the name, which the description does not explain.

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