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

Annotations already declare read-only and non-destructive behavior, and the description is consistent with that. It adds value by disclosing exactly what data is returned, including judgment text, image text, interpretations, and changing lines. It does not describe failure modes, but for a read-only lookup that is a minor gap given the annotations.

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 two purposeful sentences with no filler. The primary action is front-loaded, the return sections are compactly enumerated, and the final sentence states useful usage context.

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?

This is a simple read-only single-hexagram lookup with one required parameter, and the description fully covers the return payload without needing an output schema. Combined with 100% parameter coverage in the schema, nothing critical is missing for an agent to invoke the tool 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%, so the schema already fully explains number, lang, and compact. The description only restates that the lookup is by King Wen number (1-64) and adds no new semantic detail about lang defaults or compact behavior. Baseline 3 is appropriate.

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 opens with a specific verb and resource: retrieving I-Ching hexagram details by King Wen sequence number. The distinct 'by number' scope sets it apart from siblings like get_iching_hexagrams_random, get_iching_hexagrams_lookup, and get_iching_trigrams, and the enumerated return content confirms this is a detailed single-hexagram reader.

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 concrete usage context: display detailed hexagram information after casting or for educational reference. It does not explicitly name alternative sibling tools or say when not to use it, but the guidance is clear enough for an agent to choose this tool for a known hexagram number.

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