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

Annotations already declare readOnlyHint and idempotentHint, so no extra safety disclosure is needed. The description adds useful behavioral context by noting the data copyright and attribution requirement, which is a real condition of use. This goes beyond what annotations provide, though it doesn't cover other behavioral aspects like rate limits or pagination.

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 only two sentences: the first states the core purpose, and the second provides necessary licensing context. Both sentences earn their place, and the main function is front-loaded. No fluff or redundancy.

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 zero-parameter input schema, the readOnly/idempotent annotations, and the presence of an output schema, the description covers the essential content (the four orderings) and the licensing requirement. There is no missing behavioral or usage information that the agent would need beyond what structured fields already provide.

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 tool has zero parameters, so the baseline is 4. The description correctly avoids inventing parameter details and instead focuses on the tool's output content. There is nothing to add about parameter semantics since none exist.

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 uses a specific verb ('Describes') and resource ('the four canonical hexagram orderings') and names the exact orderings (kingwen, mawangdui, eightpalaces, binary). This clearly distinguishes it from sibling tools like list_hexagrams or get_hexagram, which focus on hexagrams themselves rather than sequence orderings.

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 gives clear context: it lists the four canonical sequence types, making it obvious that this tool is for retrieving sequence orderings. It does not explicitly mention when not to use it or name alternatives, but the purpose is sufficiently unique among the siblings, so the absence of exclusions is acceptable.

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